With David Montgomery unavailable, Damien Williams moves into the starting running back role for the Bears, starting with Sunday's game against the Raiders in Las Vegas.

Montgomery was unable to practice all week after a sprained knee forced him to exit last weekend's win over the Lions with 11:00 left in the fourth quarter. He was originally listed as out for Sunday's contest, but was placed on injured reserve Saturday and will miss a minimum of three games.

Williams, the versatile seventh-year pro, is adept at running with the ball as well as catching passes out of the backfield.

In the first four games this season, Williams rushed for 73 yards and one touchdown on 16 carries and caught eight passes for 41 yards. He signed with the Bears in March after opting out of the 2020 campaign due to COVID-19 concerns.

Prior to that, Williams appeared in 85 games with 13 starts over six seasons with the Dolphins (2014-17) and Chiefs (2018-19), rushing for 1,231 yards and 12 TDs on 294 carries and catching 138 passes for 1,106 yards and 10 TDs. He capped the 2019 season by scoring two touchdowns in the final 2:44 of Super Bowl LIV to help the Chiefs turn a 20-17 deficit into a 31-20 win over the 49ers.

"When Damien is in the open field, and you saw David do it, too, they can make you miss in space," said coach Matt Nagy. "So, they both have that. The place where they're the most similar, I think, is their mentality. I always talk about it; they've got the dog mentality. I love that about them.

"Damien is a little bit more extroverted than David. And to each their own. That means nothing, other than their personality. But I know to be able to have them both was great, and then this situation when David gets hurt, we feel like, hey, for Damien to be able to come in here and help us, we feel like we're in a good place."

Elsewhere on offense, the Bears will be thin at tight end: Jesse James (personal reasons) and J.P. Holtz (quad) have been ruled out of Sunday's game, while Jesper Horsted (knee) is listed as questionable on the injury report.

Defensively, tackle Akiem Hicks was originally listed as doubtful for Sunday's game, but was downgraded to out Saturday due to a groin injury he suffered on the Lions' first play from scrimmage last Sunday at Soldier Field.

Outside linebacker Khalil Mack will be able to face his former team in Las Vegas, however, despite injuries to his knee and ribs. The perennial Pro Bowler was limited in practice Friday after sitting out Wednesday and Thursday but said he would play. Mack revealed that he hurt his ribs while being tackled on a fumble return last Sunday when he landed on the elbow of a Lions player.

Listed as questionable, Mack was asked by a reporter how close he is to being 100 percent healthy.

"I'm going to be out there," Mack said. "If I'm out there, I'm 100 percent."

It also appears that safety Tashaun Gipson Sr. could return after missing the last two games with a hamstring injury. The eighth-year pro is questionable but was a full participant in practice all week.

In other injury news, linebacker Joel Iyiegbuniwe (hamstring) was ruled out of the game and linebacker Christian Jones (back) is questionable after being limited in practice Friday.

For the Raiders, tight end Derek Carrier (pectoral) and cornerbacks Damon Arnette (groin) and Trayvon Mullen (toe) were ruled out; and running back Peyton Barber (toe) is questionable after being limited in practice Friday. Arnette was selected by the Raiders with the 19th pick in the first round of the 2020 draft with a selection obtained from the Bears in the Mack trade.