Arizona Cardinals quarterback Kevin Kolb has been injured while being sacked against the Buffalo Bills.
Kolb was injured with just over two minutes left in Sunday's game when he tried to fall forward and two Bills players landed on him. He lay on the field for several minutes as medical personnel attended to him, then gingerly walked off the field after a cart was waved off.
The Cardinals said Kolb injured his ribs and would not return.
Kolb lost a tight battle to be Arizona's starter to open the season, but started four games after John Skelton sprained his right ankle in the opener against Seattle.
Skelton, who was active for the first time since his injury, replaced Kolb in Sunday's game.
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