David Letterman’s TV sidekick was hospitalized early Tuesday after a game of catch on the show went wrong. The talk show host was enjoying a break during the taping of CBS’ Late Show when he started passing the pigskin to stage manager, Biff Henderson, who is often involved in comedy segments for the show.

But Letterman’s last throw to his sidekick went wrong when Henderson, 63, moved to catch the ball and tumbled off the stage in front of the studio audience. Before he knew Henderson was hurt, Letterman quipped, “I can smell a lawsuit. “ After the injured Late Show stage manager began complaining of pain in his knees, he was wheeled to a waiting ambulance outside the Ed Sullivan Theater and rushed to nearby Roosevelt Hospital. Biff was treated for a leg injury and later released.