In Doug Marrone's two seasons as head coach, the Buffalo Bills' offense averaged 4.92 yards per play, the third-worst mark in the league.

It's fair for offensive coordinator Nate Hackett to shoulder some of the blame for those struggles, but running back Fred Jackson believes Hackett was being held back from doing more with the offense.

"I love Nate. I loved what he brought to the table," Jackson said during his weekly appearance on WGR 550 in Buffalo. "He was a guy that, just anybody else on the team was under fire with the lack of performance that we had as an offensive unit.

"But I could definitely see him not getting to do some of the things he wanted to. I had some conversations with him and it wasn't always, at times, what he wanted to get done."

That's a not-so-subtle shot at coach Doug Marrone, whose sudden departure last week left Jackson feeling like he had been "punched in the stomach."

When Marrone and Hackett took control of the Bills' offense in 2013, their offense was built around speed. The Bills averaged 24.7 seconds of possession per play, the second-fastest rate in the NFL.

But a variety of factors -- especially their quarterback situation -- rendered the offense that season largely inefficient. The Bills ended 39.3 percent of their drives without a first down or touchdown, the seventh-highest rate in the league.

The Bills slowed down the pace this season, averaging 28.0 seconds of possession per play (14th in the NFL), and took a more conservative approach, averaging 7.1 air yards per pass attempt (second-fewest in the NFL).

Hackett wanted to be more aggressive, according to Jackson.

"He was an aggressive guy and has always been since I've known him," Jackson said. "When some of the things that were called that didn't kind of fit his mold, that is what it is. He couldn't do what he wanted to.

"Knowing Nate, Nate is a guy that likes to go big or go home. Some of the stuff that he wanted to call, didn't get called in a game, and I don't know if that was always his call."

Hackett remains under contract with the Bills, but his future with the team is up in the air as they search for a new head coach.

"I hope the best for him," Jackson said. "He's a great coach, a guy that I loved playing for. A lot of guys loved playing for him. We'll see what happens and how everything plays out."