Kevin Kolb has possible concussion

Buffalo Bills quarterback Kevin Kolb left Saturday's preseason game with concussion-like symptoms and did not return.

Diving for a first down after an 8-yard scramble in the first quarter, Kolb appeared to get hit in the back of his helmet by the knee of Washington Redskins linebacker Brandon Jenkins. Kolb did not show any immediate signs of injury and stayed in the game for the final four plays of the drive.

Kolb was replaced by undrafted rookie Jeff Tuel on the Bills' next drive. With first-round pick EJ Manuel inactive for Saturday's game, Tuel is the only healthy quarterback left on the Bills' roster.

Before departing for the locker room, Kolb was 2-for-4 passing for 16 yards. On the first possession of the game, Kolb was sacked for a loss of 13 yards.

Kolb and Manuel had been competing for the starting job, but both have been hit by injuries this preseason. Kolb missed the preseason opener with a knee injury, while Manuel is sidelined for at least the remainder of the preseason after undergoing a minor procedure on his left knee.

With both Kolb and Manuel sidelined, the Bills will work out former Arizona Cardinals first-round pick Matt Leinart on Sunday, as well as former Redskin John Beck, a league source told ESPN NFL Insider Adam Schefter.