Buffalo Bills quarterback Kevin Kolb has concussion-like symptoms after getting kneed in the back of the helmet.
Sidelined by a concussion last season with Arizona, Kolb was hurt at the end of an 8-yard scramble in the first quarter Saturday against the Washington Redskins.
Kolb remained in the game for four more plays, until the drive ended with a 2-yard touchdown run by C.J. Spiller.
Kolb has been competing for the starting job with first-round pick EJ Manuel, but Manuel hurt his left knee in the Bills' previous game and is out for the rest of the preseason.
With both Manuel and Kolb hurt, undrafted rookie Jeff Tuel became the only healthy quarterback on the roster. Tuel entered the game on the next series.
AP NFL website: www.pro32.ap.org