ORCHARD PARK, N.Y. -- Buffalo Bills quarterback Thad Lewis did not practice Wednesday due to a rib contusion and is "50-50" to play Sunday against the Kansas City Chiefs, coach Doug Marrone said Wednesday.
X-rays were negative on Lewis, who was injured on the first play of a loss to the New Orleans Saints last Sunday. Lewis fumbled on the play but returned for the next series and played the remainder of the game.
"The doctors call it a contusion," Marrone said. "In layman's terms, I call it sore."
Lewis is also dealing with a "flu virus," according to Marrone.
Despite quarterback EJ Manuel returning to practice Wednesday on a limited basis, Marrone said that the rookie will not play Sunday. Manuel has been out since spraining his right LCL in a loss to the Cleveland Browns on Oct. 3.
In Lewis' absence, Jeff Tuel and Matt Flynn split first-team reps at quarterback Wednesday. It was the first significant practice action that Flynn has seen since signing on Oct. 14, while this is the third time Tuel, an undrafted rookie, has been considered following an injury to another Bills quarterback.
"Coach Marrone walked into the room and said 'It could be anybody. We don't know,'" Tuel said. "We know as much as you do."
Tuel completed 8 of 20 passes for 80 yards with an interception after he replaced Manuel against the Browns, his only playing time of the regular season.
"I had a lot of adrenaline flowing and nerves," Tuel said. "I learned a lot about the system and operating it."
Lewis' status for Thursday's practice remains uncertain. Marrone said he will evaluate Lewis' chances to start later in the week but indicated he may lean toward Tuel based on his experience in the offense.
"I feel better about Jeff right now, because I know Jeff," Marrone said. "That's not to say Matt's not good enough. I just haven't seen enough of Matt to really say it's a competition yet."
Lewis has been sacked 13 times in his three starts, the most in the NFL over that span. The unbeaten Chiefs, meanwhile, lead the league in sacks.
"I need to take care of myself," Tuel said. "I know we're down in quarterbacks. I have to do whatever I can do to get down."