Bills quarterback Thad Lewis missed his second straight practice on Thursday and remains questionable for Sunday's game against the Kansas City Chiefs.
Bills coach Doug Marrone reiterated Lewis has a "50-50" chance of playing after bruising his ribs in Sunday's loss to New Orleans.
If Lewis is unable to play, the Bills (3-5) will start either undrafted rookie Jeff Tuel or newly signed free-agent Matt Flynn against Kansas City (8-0). Marrone declined to say Thursday who will start if Lewis can't play.
Lewis has gone 1-2 as a starter since replacing rookie EJ Manuel, who is sidelined with a knee injury.
Marrone expects running back C.J. Spiller to return after missing Sunday's game with a high ankle sprain. Spiller was limited at practice Thursday.