In a split second, in a routine drill, the 2015 Cardinals' season could have been lost.

Tyrann Mathieu accidentally knocked running back Kerwynn Williams into Carson Palmer.

Fortunately, Palmer came away unscathed. The signal caller is still trying to get back to 100 percent after undergoing surgery to repair a torn ACL last November.

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Palmer did get the next day off, but it wasn't necessarily a result of the scare. The coaching staff and Palmer had agreed to terms on going through with this plan prior.

"It was something that was set in stone months ago," Palmer said, via Bob McManaman of the Arizona Republic. "It was something I argued with for probably six weeks and I just gave up because I realized I was getting nowhere with it."

Perhaps it's better that Palmer get a day off here and there throughout training camp. It should only help since the 35-year-old is coming off his second major surgery.

If the Cardinals are to contend in the NFC, they'll need Palmer at 100 percent, and nothing less.

(h/t ProFootballTalk)