"On take one of my finale routine, which we rehearsed and rehearsed and rehearsed and rehearsed, my dance partner did something unrehearsed, and the result was me hearing a loud rip and a pop," he said. "It was my bicep."
Manganiello powered through the scene -- "which involves a sex swing with monkey bars on top" -- despite his injury but Vergara, who was on set at the time, wasn't too pleased.
"We got back to my trailer and, as soon as the door closed, she said, 'If I see you at the gym tomorrow, we're done!'," he joked. "'I'm going to leave you! That's it!'"