Running back Jamaal Charles reinjured his surgically-repaired left knee on Sunday against the Bills, but he isn’t expected to miss any games, coach Romeo Crennel said. (US Presswire)

Kansas City RB Jamaal Charles reinjured his surgically-repaired left knee on Sunday, coach Romeo Crennel told the Kansas City Star on Monday.

This helps explain why Charles carried the ball only six times against the Bills and spent part of the second half on the exercise bike on the sideline.

"He got banged up a little bit and we decided not to put him back in the game. He wanted to go back," Crennel said. "He wanted to go back in … but the other guys were doing OK, so we left the other guys in.

"I talked to him after the game. He said he wanted to go back in and he felt OK. He was getting treatment, so I think he'll be ready to play this week."

Charles tore his ACL in his left knee in the second game of 2011. The Chiefs were cautious with Charles throughout training camp, often limiting his work, and it's not surprising they were cautious in a blowout loss.

Charles ran for only three yards against the Bills and also caught three passes for 19 yards. RBs Peyton Hillis and Shaun Draughn were in the game for more plays than Charles.

Follow Chiefs reporter C.J. Moore on Twitter @CBSChiefs and @cjmoore4.