Several of Kolb's ribs reportedly were detached from his sternum. (US Presswire)

After rescuing the Cardinals in Week 1 while spelling an injured John Skelton and leading his team to a win (and an undefeated record through the first four weeks of the season), quarterback Kevin Kolb was playing some of the best football of his career.

But on Sunday, Kolb suffered a sternum injury when he was crushed between two Bills defenders. Now, CBS Sports' Jason La Canfora reports that Kolb will miss at least six weeks due to his sternum and shoulder injuries

According to ESPN’s Adam Schefter, multiple ribs were detached from Kolb's sternum, and he also suffered a sprained sternoclavicular joint in his chest on the play in which he was crushed by Chris Kelsay and Alex Carrington.

Skelton, who sprained his ankle in Week 1, was healthy enough to enter the game in place of Kolb and finished the drive that led to a game-tying field goal.

But Skelton -- who finished 2 of 10 for 45 yards-- was intercepted in Arizona territory in overtime, and two plays later Buffalo won the game with a 25-yard field goal.

"John made a couple of good throws for us; the fourth-down throw to Larry [Fitzgerald] was a big-time throw," coach Ken Whisenhunt said. "And the throw to Larry on the slant that put us down on the 20-yard line was another good throw. But the interception was not. That was one where you can't make that throw.

"John did well enough in there to give us a chance to win at the end of regulation. Had we made that kick, we would have felt good about everything."

While the Kolb news obviously is disheartening, the Cardinals can take solace in the fact that when Kolb was lost for the season after suffering a concussion last year, Skelton led the team to a  5-2 record in the final seven weeks.

Of course if the Cardinals' shoddy offensive line play continues (Kolb was sacked 23 times in the past three weeks), Skelton's success from last year probably won't matter a bit.

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