GREEN BAY – Now the cram session begins.

The Packers' newest running back, Knile Davis, arrived in Green Bay just a few hours before practice on Tuesday. He got a quick orientation, his equipment, and was on the field right away to do scout-team and special-teams work in preparation for Thursday night's game against the Bears.

He hadn't even gotten a chance to study the playbook yet, but that was next on his agenda after a brief meeting at his locker with local reporters.

"All day today, all day tomorrow, before the game, trying to learn as much as I can," Davis said of his objective between now and kickoff.

"I'm not sure what they want to do. They haven't laid it out for me. I'm sure it's like a gameday decision, but I'll be ready."

The Packers acquired Davis in a trade with Kansas City for a conditional draft pick to fortify the running back position with Eddie Lacy (ankle) not practicing and James Starks (knee) out at least a couple of weeks.

The Chiefs' third-round draft pick out of Arkansas in 2013, Davis had a combined 610 rushing and receiving yards and seven TDs in his second season but had since fallen to fourth on Kansas City's depth chart with the additions of Charcandrick West and Spencer Ware the past two years. He had just one carry and two receptions in games this season.

Davis was shocked to find out about the trade Monday night while enjoying a "victory Monday" playing some video games (the Chiefs beat the Raiders on Sunday), but he feels as though his football career has been given new life.

"I feel like I'm off the range," Davis said. "I've been on the sideline, been itching to be in the game and be a part of the team, which I was in Kansas City, I did what I could. I'm just excited to be a part of Green Bay and hopefully my role gets bigger."

What role he might have, if any, on Thursday night remains to be seen. The Packers' current No. 2 back is Ty Montgomery, but the 5-10, 227-pound Davis brings a speed dimension that'll be new to Green Bay's backfield, and he'd be a more traditional back in reserve behind Lacy.

Arriving on a short week isn't ideal as far as getting prepared to play right away, but a small package of plays could be learned in time if need be.

Davis is up for whatever the coaches want to throw at him, on offense or special teams. He'll be studying the playbook and game plan as fast as he can.

"It's putting what you already know with what they know, and not getting confused with terminology that meant something else where you were at," he said. "Once I get that down, I think I'll be good.

"It feels like getting drafted again. A new beginning, and I'm excited."

Linsley returns: Third-year center Corey Linsley practiced for the first time this season on Tuesday.

He was placed on the physically unable to perform (PUP) list at the start of training camp due to a hamstring injury that he re-aggravated after missing the bulk of the offseason program. He then began the regular season on PUP, which required him to sit out the first six weeks.

"It felt great," Linsley said of finally getting back on the practice field. "It's been a long time, since January.

"It was the conservative approach to begin with, putting me on PUP. It looks like it's paid off health-wise. I feel fresh, feel good."

Fourth-year pro JC Tretter has taken over as the Packers' starting center. That's the job Linsley took from Tretter two years ago due to similar injury circumstances. Linsley doesn't know what the immediate future holds for him, but that's how this business works.

"It's always the next guy in. I was in that place at one point," he said. "It (stinks), personally, but that's being selfish. You want to watch your team succeed no matter what. I think we're on a great path. We hit a bump in the road, but I think this team is headed in the right direction."

Now that Linsley has started practicing, the Packers have a 21-day window within which he'll have to be placed on the active roster to be eligible to play this season.

"It's up to them," he said. "It's more than just me being healthy. It's all the roster stuff. I'm ready whenever."

Hodkiewicz: Packers' cornerbacks pull together in face of adversity