David Letterman has shown some verbal muscle in the past month during his tussle with Jay Leno, and on Monday he showed some physical strength as well when he knocked over long-time stage manager Biff Henderson with a football toss, sending him to the hospital.

While waiting on-set for the arrival of New Orleans Saints quarterback Drew Brees, who was stuck in traffic, Letterman fired a pass to Henderson. "I caught it," he said, according to the NY Daily News, before falling off the stage and nearly into the laps of several 'Late Show' audience members.