"Quarterback Matt Cassel's return to Chiefs practice barely caused a ripple in the locker room once it concluded. Other than some bruised feelings caused by the blowout loss to San Diego in his absence, it was hard to tell he was ever missing.

In fact, to wide receiver Terrance Copper, if you hadn't known Cassel had an appendectomy last week, you wouldn't have figured it out at practice on Wednesday.

"Matt looked like the old Matt," Copper said. "He always looks the same to me."

The Chiefs listed Cassel as being a limited participant in practice and called his availability for Sunday's game against the Rams in St. Louis as day to day. In doing so, they served notice they will take this issue to the end of the practice week on Friday if not all the way up to game time before it is resolved.

"It will truly be a day-to-day thing," coach Todd Haley said. "That's not at any kind of level secrecy. We just have to see how he responds each day."

The 8-5 Chiefs are trying to retain their hold on first place in the AFC West. They are a game ahead of the 7-6 Chargers, who could put more heat on the Chiefs by winning tonight at home against San Francisco.

With Cassel watching the game in Kansas City, nothing worked properly for the Chiefs last week in San Diego. Brodie Croyle played at quarterback and the Chiefs lost 31-0.

That Cassel is back so quickly at practice is a positive sign for the Chiefs but doesn't yet mean he will play against the Rams. Asked to put a percentage on the chance he would play in St. Louis, Cassel said, "Hopefully 99.99999 percent."

Then, getting serious, he said, "I really don't know."

The decision rests with the Chiefs and whether they believe Cassel can play effectively. That's something they watched carefully on Wednesday and will continue to monitor for the next two days.

"Right now, it's more how I feel and how the week progresses," Cassel said. "It's also how the coaches evaluate me throughout the week and whether I can make the throws and play to the best of my ability."