A three-year starter at USC, Leinart ranks No. 3 on the Trojans' career passing list. He won the 2004 Heisman Trophy as a junior and was the No. 10 overall pick in the 2006 draft by the Arizona Cardinals.

Leinart went 4-7 as a starter his rookie year and was 3-2 in 2007 before suffering a broken collarbone. He was never a No. 1 NFL quarterback again and was released by the Cardinals prior to the 2010 season after getting beat out by Derek Anderson. He also served as a backup for the Houston Texans and Oakland Raiders and was out of the NFL after six seasons, 15 touchdown passes and 21 interceptions.

Jackson was the rare athlete who possessed the power, speed and skill to not just play professionally in two sports but be a star in both. He won the 1985 Heisman Trophy as a senior at Auburn and was selected at No. 1 by the Tampa Bay Buccaneers in 1986. He refused to play for the Bucs and wound up with the Oakland Raiders a year later. By then he was in his second pro baseball season with the Kansas City Royals. Jackson played both sports from 1987 to 1990, and he was an All-Star outfielder in 1989 and a Pro Bowl running back in 1990.

Jackson's baseball commitment cut into his football production, but worse, a hip injury ended his NFL career after just four seasons and shortened his baseball career. After the injury, Jackson managed to play in parts of three more baseball seasons. He was 31 when he played his last game as a pro athlete, leaving us to wonder what could have been if he'd stayed healthy or focused on one sport.

An explosive running back, Carter rushed for 1,539 yards and 23 touchdowns for Penn State in 1994 and finished second in the Heisman voting. He averaged 7.16 yards per carry during his college career. The Cincinnati Bengals traded up from the fifth spot to make him the No. 1 pick in 1995.

Carter tore the ACL in his left knee in his first preseason game and missed the 1995 season. He appeared in all 16 games in 1996, but he was never the same player. Injuries would plague him for the rest of his career, too. Carter totaled fewer rushing yards (1,144) and touchdowns (20) during an NFL career that included parts of seven seasons than he did in his final year at Penn State.

In the mid-1990s, Bill Pulsipher, Jason Isringhausen and Paul Wilson formed a trio of hard-throwing young pitchers for the Mets, nicknamed for the scorebook abbreviation for a strikeout. Pulsipher and Isringhausen debuted for New York in 1995, and Wilson, the No. 1 pick in 1994, arrived in the majors in 1996.

The three were never on the Mets' active roster at the same time, as a slew of injuries forced them out for long stretches and stunted their development. They all eventually became contributors elsewhere, but none became a top-line starter. Isringhausen carved out the most notable career, earning two All-Star berths as a closer in Oakland and St. Louis.

Tarpley, the 1984-85 Big Ten Player of the Year at Michigan, was the No. 7 pick of the 1986 draft by the Dallas Mavericks. In his second season, the 7-footer was the NBA Sixth Man of the Year and posted playoff averages of 19.4 points and 14.0 rebounds as the Mavs came within one game of reaching the 1988 NBA Finals.

After multiple suspensions for violating the NBA's substance-abuse policy, Tarpley was banned indefinitely in 1991 for using cocaine. He was reinstated after missing three years, but the comeback lasted just one season. He was permanently banned in 1995 for violating the terms of his aftercare program.

The mammoth Mandarich was touted on the cover of Sports Illustrated as "the best offensive line prospect ever" when he came out of Michigan State in 1989. The Green Bay Packers selected him second overall, just ahead of Barry Sanders, Derrick Thomas and Deion Sanders -- all Hall of Famers.

The Packers made Mandarich the highest-paid offensive lineman in NFL history, but he didn't start a game as a rookie and was released after three seasons. He was out of the NFL for five years before spending three seasons with the Indianapolis Colts. Considered one of the biggest draft busts in NFL history, Mandarich later admitted to using steroids throughout his college career.

Henson was good enough in two sports to play third base in the Yankees organization while sharing time with Tom Brady at Michigan. When rating him as MLB's ninth-best prospect in 2002, Baseball America declared, "It's definitely his destiny to don the pinstripes."

The Yankees drafted Henson out of high school in 1998, but in parts of six seasons with the organization, he accumulated more strikeouts (559) than hits (461). He'd played quarterback for Michigan from 1998 to 2000 and returned to football in 2004 after falling out of the Yankees' plans. But Henson appeared in just nine NFL games -- seven of them with the Dallas Cowboys -- and threw 20 career passes.

Tony C. belted 24 home runs as a 19-year-old rookie for the Boston Red Sox in 1964 and led the American League with 32 long balls the next year. On July 23, 1967, the slugging outfielder became the youngest AL player to reach 100 career home runs.

On Aug. 18, 1967, a stray Jack Hamilton fastball struck Conigliaro in the left side of his face, damaging his eye, cracking his cheekbone and dislocating his jaw. The injuries sidelined him through the next season, but Conigliaro returned with 20 home runs in 1969 and 32 more in 1970. His vision faltered, however, and he hit just six more home runs in parts of two seasons.

Hernandez won the 2009 John Mackey Award, presented annually to college football's best tight end, as a junior at Florida. The Patriots drafted him in the fourth round in 2010 and teamed him with Rob Gronkowski to form a formidable tight end tandem. After Hernandez caught 79 passes for 910 yards and seven touchdowns in 2011, New England rewarded him with a five-year extension that included a $12.5 million signing bonus -- a record for a tight end. "I'm glad it worked out," coach Bill Belichick said of the deal.

The Patriots released Hernandez on June 26, 2013, after he was arrested on murder charges. He was found guilty in 2015 and sentenced to life in prison.

Young went 30-2 as Texas' starting quarterback and led the Longhorns to a national championship by defeating USC in the 2006 Rose Bowl, prompting the Titans to make him the No. 3 pick in the 2006 NFL draft.

Young went 30-17 as a starter for the Titans and was named to two Pro Bowls, but he clashed with head coach Jeff Fisher and was sidelined by knee and thumb injuries. After the Titans released him in 2011, Young had a brief stint with the Eagles before getting signed and quickly released by the Bills, Packers and Browns without playing for any of them. He announced his retirement in 2014, shortly after filing for Chapter 11 bankruptcy protection.

Described by Sports Illustrated as "America's first test-tube athlete," Marinovich was groomed to be a quarterback by his highly controlling father, who dictated every aspect of his diet and conditioning. Despite an uneven college career at USC and an arrest for cocaine possession, Marinovich was a first-round pick by the Raiders in 1991 -- selected ahead of Brett Favre.

Marinovich appeared in only eight regular-season NFL games in 1991 and '92 before being suspended for repeatedly failing drug tests. He briefly spent time in the CFL and Arena Football League, but drug problems kept resurfacing. He once received a signing bonus from an AFL team and was arrested for buying heroin the same day.

The powerhouse running back led Nebraska to a national championship in 1994. Although his 1995 season was interrupted by an arrest for assaulting an ex-girlfriend and a subsequent six-game suspension, the Rams made him the No. 6 pick in the 1996 draft, with owner Georgia Frontiere saying Phillips "is going to be just fine."

Phillips wasn't just fine. He lasted less than two seasons with the Rams and spent 23 days in jail during that time. He had brief tenures with the Dolphins and 49ers, but repeated off-field problems and escalating issues with coaches ended his NFL career in 1999. He continued to have legal problems and killed himself in his prison cell earlier this year.

Smith threw 32 touchdown passes during his senior year at Oregon, raising his stock to the point that the Bengals made him the No. 3 pick in the 1999 draft. "A lot of people had him No. 1 on their boards," Bengals coach Bruce Coslet said at the time. "I'm very pleased."

Smith missed his initial training camp because of a contract holdout, never jelled with the Bengals' offense and was benched in 2000. "I'm kind of baffled that they drafted me," he said, echoing the thoughts of many Bengals fans. Smith's NFL career ended after four seasons and a 3-14 record as a starter, and he later flopped in NFL Europe and the CFL, as well.

The sky seemed to be the limit when the Padres made Bush, a San Diego high school star, the No. 1 pick in the 2004 draft. "Bush has one of the best arms I've ever scouted," said Padres scouting director Bill Gayton.

The right-hander still hasn't made it to the bigs, largely because of a long-running drinking problem that led to a series of arrests and culminated in a three-year prison stint for DUI. He was released from prison this past October and is pursuing a comeback. He went to spring training with the Rangers and started the season at Double-A Frisco. He's one of three No. 1 picks (not counting the past three drafts) to never reach the majors, the other two being Steve Chilcott (in 1966) and Brien Taylor (1991, see No. 9 below).

"The Boz" was a two-time consensus All-American and the only player to twice win the Dick Butkus Award as the nation's top linebacker. The flamboyant star helped Oklahoma win the 1985 national championship, but he was a lightning rod for controversy. The Seattle Seahawks picked him in the first round of the 1987 supplemental draft and signed him to a 10-year, $11 million deal, then the biggest rookie contract in NFL history.

Bosworth's skills didn't translate to the NFL, and he was forced to retire after playing in just 24 games. A shoulder injury in 1988 effectively ended his career, and he played just two games in 1989 before leaving the game and transitioning into an equally disappointing acting career.

Russell compiled a 21-4 record as a starter for LSU and was named MVP of the 2007 Sugar Bowl, capping a season in which he completed 67.8 percent of his throws. At 6-foot-5, 265 pounds and with a rocket for an arm, Russell wowed scouts at the combine and was selected with the No. 1 pick by the Raiders in 2007. After a lengthy holdout that dragged through training camp and the start of the season, Russell signed a six-year, $68 million deal, with $31.5 guaranteed.

Things didn't get any easier for Russell after the delayed start. He lasted just three seasons before the Raiders released him. He went 7-18 as an NFL starter with 18 touchdown passes, 23 interceptions and a completion percentage of 52.1. Russell, now 30, recently said he'd play for free if a team would give him another chance.

The Yankees selected Taylor, whose fastball registered in the upper 90s, out of high school with the No. 1 pick in 1991. Agent Scott Boras called the left-hander "the best high school pitcher I've seen in my life" and helped him secure a $1.55 million contract. In his first two years of pro ball, Taylor struck out 337 batters in 324 1/3 innings.

In December 1993, a week before his 22nd birthday, Taylor injured his shoulder in a fight, reportedly while defending his brother. He missed the entire 1994 season and wasn't the same after he returned. Taylor never played above Double-A and was released by the Yankees in 1998.

Touted by some as "the next Pele," Adu -- at age 14 -- became the youngest athlete to sign a professional contract in the United States after DC United selected him in the 2004 MLS SuperDraft. Before turning 15, the Ghana native, who moved to the U.S. at age 8, became the youngest player to appear in an MLS game and the youngest to score a goal.

Despite a promising start to his career, Adu never lived up to his lofty expectations. He has become a journeyman, playing for 13 teams in eight countries by the age of 26. He currently plays for the Tampa Bay Rowdies of the North American Soccer League, a Division II league below MLS.

Clarett was one of the best freshman running backs in college history, rushing for 1,237 yards and scoring 18 touchdowns while leading Ohio State to a 14-0 record and a BCS championship in 2002.

The Buckeyes dismissed Clarett from the program before the 2003 season after he was charged with filing a false police report. He unsuccessfully challenged the NFL's draft eligibility rules and had to sit out until 2005, when the Denver Broncos selected him in the third round. Clarett reported to training camp overweight and was a shell of his former self. The Broncos cut him one month after he signed a four-year contract, and he never played a down in the NFL.

Prior was one of the greatest pitching prospects in recent memory when the Chicago Cubs drafted him with the No. 2 pick in 2001. He was considered a can't-miss prospect by most scouts when he signed a record $10.5 million contract.

Prior showed glimpses of living up to his potential -- when healthy. He finished third in Cy Young voting in 2003 after compiling an 18-6 record, but that would be the high-water mark of a career that lasted just five seasons because of arm problems. Prior last pitched in the majors in 2006; he had failed comeback attempts with the Padres, Rangers, Yankees, Red Sox and Reds before finally retiring in 2013.

A McDonald's All-American in 1999, Williams averaged 19.3 points and 6.0 assists in three brilliant seasons at Duke and was named national player of the year as a junior. He was selected No. 2 in 2002 by the Chicago Bulls, who expected Williams to be a franchise point guard for years to come. He averaged 9.5 points and 4.7 assists per game in what would be his only NBA season.

Traumatic injuries -- including nerve damage in his left leg and a broken pelvis -- suffered when he crashed his motorcycle after his rookie season curtailed his promising career. He attempted a comeback, signing with the New Jersey Nets at one point, but he never played in another NBA game. Williams is now a college basketball analyst for ESPN.

Standing 6-foot-5 and possessing a rocket arm, Leaf emerged on the scene in 1997 by leading Washington State to its first Rose Bowl berth in 67 years. In three seasons with the Cougars, he compiled 7,433 passing yards and 59 touchdowns. There were serious debates about whether he or Tennessee standout Peyton Manning should be the No. 1 pick in 1998.

Leaf had to suppress yawns at his introductory news conference in San Diego the day after being drafted No. 2 by the Chargers. Turns out he had stayed out late partying the previous night in Las Vegas, foreshadowing career turbulence. Questions about dedication and work ethic dogged Leaf, who produced two dismal statistical seasons with the Chargers -- a 4-14 record with a 48.8 passer rating, 13 touchdowns and 33 interceptions -- and missed a third to injury. He was out of the league by 2002.

Dupree was one of the most highly recruited players in college football history after rushing for more than 7,000 yards as a high schooler in Mississippi. He chose Oklahoma, where he ran for 1,144 yards and 13 touchdowns as a freshman and averaged a gaudy 7.8 yards per carry.

Dupree left the Sooners during an injury-riddled sophomore season, transferring to Southern Mississippi but never playing a game there. He turned pro in 1984 at age 19, signing with the USFL's New Orleans Breakers. He had moderate success while battling injuries that season, then tore an ACL in the 1985 opener. Five years later, at age 26, Dupree made a comeback with the Los Angeles Rams and played sparingly over two seasons.

Bowie had emerged as one of the nation's top players by his sophomore season at Kentucky, averaging 17.4 points and 9.1 rebounds. A stress fracture in his left tibia knocked him out for the next two seasons, however, and he averaged 10.5 points and 9.2 rebounds as a senior. Still, the Trail Blazers gambled on the skilled 7-footer with the No. 2 selection in 1984.

Bowie suffered several more leg injuries early in his NBA career, limiting him to just 139 games in his first five seasons. He enjoyed four solid seasons after being traded to the Nets before wrapping up his career with the Lakers. Yet the Trail Blazers' selection of Bowie will always be judged critically because of the player taken right after him -- North Carolina guard Michael Jordan.

Oden led Ohio State to the championship game of the 2007 NCAA tournament as a freshman while averaging 15.7 points, 9.6 rebounds and 3.3 blocks per game. He was drafted No. 1 in 2007 by the Trail Blazers, ahead of Kevin Durant, and embraced the hype, fearlessly telling ESPN The Magazine, "I hope I can get a bunch of championships -- like 15."

Like Bowie before him, Oden was besieged by injuries in Portland. He underwent microfracture surgery on his right knee before he ever played an NBA game, and a string of subsequent injuries and surgeries led the Trail Blazers to waive him in 2012 after he'd appeared in just 82 games for them. Oden resurfaced in a limited role with the Heat in 2014, but he hasn't played in the NBA since.