LAKE FOREST, Ill. (AP) If Jeremy Langford is a little amped up for the Chicago Bears' game at San Diego on Monday night, it would not be hard to see why.

Langford said he is ''very excited'' to make his first start with Matt Forte expected to sit out because of a knee injury.

The rookie running back has some big cleats to fill. But quarterback Jay Cutler says he is ready to go with Langford.

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''We have no choice,'' Cutler said. ''Matt is not coming back. Not this game anyway, I don't think. We're going to have to work with the young kid, and like I said, he makes it easy.''

Forte walked to the locker room after he got hit in the right leg by Minnesota's Harrison Smith following a reception early in the third quarter of Sunday's loss. He sat out practice Thursday and Friday.

Coach John Fox has said he does not think the injury will require surgery or end Forte's season. But with his 30th birthday next month and his contract set to expire, there is plenty of speculation that one of the most successful running backs in franchise history could be on his way out.

Forte has only missed five games in eight seasons. But he is approaching an age when running backs tend to slow down. His best years could be behind him by the time the Bears are ready to compete again.

For now, it looks like Langford will get his turn. A fourth-round draft pick out of Michigan State, he ran for 1,522 yards and 22 touchdowns last season after rushing for 1,422 and 18 scores in 2013. He started out as a cornerback and receiver for the Spartans.

For the Bears, Langford has 27 carries for 80 yards. He ran for 46 yards on 12 attempts last week. But teammates and coaches insist he is quick learner with the athleticism to succeed in the NFL.

''It's unfortunate that we lose Matt,'' veteran left tackle Jermon Bushrod said. ''(Langford) has to step up.''

Bushrod is impressed by Langford's patience with the ball and ability to hit the hole. Cutler also praised his approach and his understanding of protections.

''If you tell him something, he already knows it,'' Cutler said.

And offensive coordinator Adam Gase says he has been ''surprised'' by how quickly he has ''picked everything up.''

Langford, meanwhile, insisted he is ready and comfortable carrying the load. He also credited Forte for helping prepare him. Forte gave Langford an up-close look at his offseason regimen - which includes uphill wind sprints - when they worked out together in the offseason.

''He's been a great influence since I've been here in OTAs and minicamps,'' Langford said. ''He's been helping me out. I feel like I'm in a great position, I'm blessed to be behind a running back like Matt who's willing to help me out and teach me along. Even now when he's not playing, he's still teaching me.''

Notes: Besides Forte, WR Eddie Royal (knee) and C Hroniss Grasu (neck) remain sidelined. LB Pernell McPhee (knee) also sat out practice the past two days. ... Gase insisted he is not thinking about the possibility of landing a head coaching job, although he figures to be sought after with Cutler thriving under him. ''That stuff's so far away,'' Gase said.

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