In this image taken from video, Yankees manager Joe Girardi,...

In this image taken from video, Yankees manager Joe Girardi, right, helps Mariano Rivera, top center, after Rivera twisted his right knee shagging fly balls during batting practice. (May 3, 2012) Credit: AP Photo/YES Network

Mariano Rivera was injured while chasing down a fly ball during batting practice on Thursday. The closer is currently undergoing an MRI for what the Yankees have termed a "twisted right knee."

Check out video of Rivera's injury and the reaction of Yankees players and coaches as it happens:

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