(Tony Avelar / AP) (Tony Avelar / AP)

As improbable as it may seem, Matt Leinart could go from watching the NFL on his couch to playing for the Buffalo Bills.

The Bills, who lost Kevin Kolb to a concussion over the weekend, signed the former USC quarterback, who played last season with the Oakland Raiders. The Heisman Trophy winner and No. 10 overall pick in the 2006 draft by the Arizona Cardinals, he also played for the Houston Texans — using the word “played” loosely. Over seven NFL seasons, he has thrown for 4,065 yards and 15 touchdowns, with 21 interceptions.

Buffalo, however, had little choice after Kolb, who has a lengthy history of concussions, suffered one that may end his career Saturday in the game against the Washington Redskins. Kolb was hurt on a seemingly innocent play, hitting his head as he fell to the turf on a keeper. He stayed in for a few plays, then left and, afterward, showed troubling symptoms.

The Bills announced that Jeff Tuel would start in the Sept. 8 opener, which would leave Leinart as the backup if rookie E.J. Manuel is stilll recovering from knee surgery.

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