"The Chiefs began preparing Wednesday for their biggest game in years without their starting quarterback.

The Chiefs also face the possibility that Matt Cassel won't play Sunday against the Chargers in San Diego. Cassel had an appendectomy Wednesday.

The 8-4 Chiefs can take a huge step toward winning their first AFC West title since 2003 by beating the 6-6 Chargers, the four-time defending division champions. Brodie Croyle would start at quarterback against the Chargers if Cassel is unavailable.

Croyle, who took the first-team snaps in practice on Wednesday, hasn't played this season. He is 0-9 as an occasional starter for the Chiefs during 2007-09.

"I've just got to prepare the same way I always do," Croyle said. "It's no different than any other week."

Things are certainly different for the Chiefs. They could also be without Cassel for the following week's game against the Rams in St. Louis and perhaps beyond.

But Cassel could conceivably play against the Chargers. Matthew Lublin, a general surgeon at St. John's Health Center in Santa Monica, Calif., said perhaps 90 percent of appendectomies are performed through laparoscopic surgery.

If Cassel had that type of surgery, it wouldn't be out of the question he could play against the Chargers, Lublin said.

"If he feels up to it, I certainly don't see any reason he couldn't play," Lublin said. "In any surgery, you're really recovering from the scar. It's a small scar he'll have since I assume it was done laparoscopically.

"He's not at a risk of popping or bursting or breaking anything or having any complication from surgery. It's really a matter of his pain threshold and how he feels. If he feels OK, I think he would be able to play.

"I'd be very impressed if he felt good enough to play Sunday. But I would not say it's out of the realm of possibility."

The Chiefs have yet to publicly rule Cassel out of Sunday's game. Coach Todd Haley at first declined to disclose the reason for Cassel's absence from practice, saying only that an illness had kept him away."