By Dan Durkin-

(CBS) Bears offensive tackle Jermon Bushrod (knee) and defensive tackle Jeremiah Ratliff (concussion) won’t play in Sunday game against the Panthers in Charlotte, Chicago coach Marc Trestman said Friday.

Bushrod suffered a knee injury when he went to the ground during a drill in Wednesday’s practice. Ratliff hasn’t played since suffering a concussion in Week 2 against the 49ers.

The hope for the Bears is that left guard Matt Slauson — who is listed as questionable now after originally being called probable — can return from his ankle injury and play Sunday for the first time since the season opener. If so, Michael Ola will man the left tackle spot in Bushrod’s place, Trestman said.

Rookie defensive tackles Ego Ferguson and Will Sutton will continue to have bigger roles with Ratliff out.

In addition, the Bears have ruled out linebacker Shea McClellin (hand) and safety Ahmad Dixon (hamstring).

Center Roberto Garza (ankle) and defensive back Sherrick McManis (quad) are both doubtful now after initially being listed as questionable Friday.

Williams to get shot as KR

On Tuesday, the Bears elevated receiver/returner Chris Williams from the practice squad to the active roster. As expected, Williams will be the lead kick returner this weekend against the Panthers, Trestman confirmed.

“Right now, Chris Williams will be available,” Trestman said. “That’s where we’ll probably start with Senorise (Perry) as the up returner. That could change as well.”

Williams was the player the Bears hoped would win the job in training camp, but a hamstring pull cost him a spot on the initial 53-man roster. The Bears are still searching for a boost in field position and with this change, they will have their third kick returner in five games.

Recently signed Teddy Williams will a four-phase core player.

Marshall a full-go for Sunday 

For the first time since the season opener, wide receiver Brandon Marshall has been a full participant in every practice for a week.

Marshall has a long-standing chemistry with quarterback Jay Cutler, but practice is essential for timing and on-field tweaks that are made to the game plan. Last week, the two weren’t on the same page, which resulted in an interception. This week, Marshall has had no limitations and has been a part of the full game plan install.

“There’s been nothing debilitating in his performance on the practice field at all,” Trestman said. “He’s practiced fast, full speed, made all the cuts and ran all the routes.”

Dan Durkin covers the Bears for CBSChicago.com and is a frequent contributor to 670 The Score. Follow him on Twitter at @djdurkin.