Linebacker Justin Houston didn't practice on Wednesday in order to rest his knee. 

"We're going to back off him today," Chiefs coach Andy Reid said. "He has some swelling in his knee and we'll get that taken care of. We don't think it's a big thing. It just comes with the territory of where he's at with the recovery part of this. It's very common." 

Houston had surgery on his knee in the offseason and missed the first nine games of the season before returning on Nov. 20 against the Tampa Bay Buccaneers. He was listed as questionable before last Sunday's game against the Tennessee Titans because of his knee but ended up playing 51 of the team's 66 defensive snaps. 

Cornerback Phillip Gaines was also absent from practice as he continues to recover from a knee injury. Gaines missed last week's game against the Titans because of the injury.

Reid said Gaines was "making improvement" but isn't quite ready to return to practice. 

Linebacker Tamba Hali also didn't practice on Wednesday, which is normal.