Bills QB Lewis misses 2nd straight practice with bruised ribs; questionable vs Chiefs

Buffalo Bills quarterback Thad Lewis (9) passes during the first half of an NFL football game against the New Orleans Saints in New Orleans, Sunday, Oct. 27, 2013. (AP Photo/Bill Feig) (The Associated Press)

Buffalo Bills quarterback Thad Lewis (9) passes under pressure from New Orleans Saints outside linebacker Junior Galette (93) during the second half of an NFL football game in New Orleans, Sunday, Oct. 27, 2013. (AP Photo/Bill Feig) (The Associated Press)

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.