Bills acquire 2 QBs; Kolb has 'serious' concussion
The Bills signed 2004 Heisman Trophy winner Matt Leinart, a former first-round draft pick, and they traded linebacker Chris White to the Detroit Lions for quarterback Thaddeus Lewis.
Meanwhile, there is concern for Kolb.
According to ESPN's Adam Schefter, Kolb suffered a concussion in Saturday's preseason loss to the Washington Redskins.
The source told Schefter that Kolb's concussion is considered "serious" and could be career-ending.
He will undergo a series of tests to determine the extent of the problem, and the Bills have no plans to rush him back into action even if he can continue his career.
Kolb was kneed in the helmet by a Redskins defender while diving for a first down on Saturday. He remained on the field for the final four plays of the drive before leaving the game with what was called concussion-like symptoms.
Kolb missed time in 2010 and 2012 with concussions.
Manuel is out for the remainder of the preseason with a knee injury. His return is questionable for the Bills' regular-season opener on Sept. 8 against the New England Patriots.
That left undrafted rookie Jeff Tuel as the Bills' only healthy quarterback, so the Bills acquired two quarterbacks Sunday.
Leinart was most recently a member of the Oakland Raiders. He has started 18 games since being drafted 10th overall by the Arizona Cardinals in 2006. The 6-foot-5 USC product has completed 366 of 641 passes for 4,065 yards with 15 touchdowns and 21 interceptions in his NFL career.
After four seasons in the desert, Leinart spent 2010-2011 as a backup with the Texans, before moving on to Oakland last season.
In April, Leinart lost out to Brady Quinn in a tryout for a backup job with the Seattle Seahawks.
Lewis spent the 2011-12 seasons on the Cleveland Browns practice squad and their 53-man roster.
He started the Browns' 2012 regular-season finale against Pittsburgh and was 22-for-32 for 204 yards with a touchdown and an interception. That game represents Lewis' only regular-season game experience.