Thad Lewis doubtful against Chiefs

ORCHARD PARK, N.Y. -- Buffalo Bills quarterback Thad Lewis (ribs) is listed as doubtful for Sunday's game against the Kansas City Chiefs after returning to practice Friday.

The Bills have yet to make a decision on which backup quarterback -- Jeff Tuel or Matt Flynn -- will start if Lewis cannot play.

"We're really going to take a good look later on this afternoon," coach Doug Marrone said. "We're going to have discussions this afternoon and tomorrow [about] which quarterback gives us the best chance to win. That's not finalized."

Lewis, who did not practice Wednesday or Thursday, was a limited participant in Friday's practice. In his place, Marrone said Tuel received more reps with the first-team offense.

"It's a point of the soreness of the ribs," Marrone said. "Really just being able to turn and throw. That's the one thing that's holding him back. If he can get by that, then he will be able to play."

Marrone said Lewis worked on footwork and timing Friday; he did not throw any passes during the portion of practice open to reporters.

"When you're dealing with muscle injuries, they take you all the way up until game time," Marrone said. "This one is a pain tolerance situation, to see what he can do."

Meanwhile, running back C.J. Spiller (ankle) and wide receiver Stevie Johnson (hip) are probable to play Sunday.