The 2014 psychological thriller Foxcatcher featured intense on-screen battles between wrestlers Mark Schultz and John du Pont, played by Channing Tatum and Steve Carell.
In a recent interview, host Sean Evans asked Ruffalo about reports he accidentally popped Tatum's ear during a take.
"Fact or fiction: is it true that you once accidentally popped Channing Tatum‘s ear during a particularly physical scene in Foxcatcher, where he told you before the take, ‘Just slap the sh*t out of me?'” the host asked.
Ruffalo confirmed Tatum had indeed told him to "slap the s*** out of" him in character.
"He did ask me to slap the s*** out of him, and it was easy to do because he’d beaten the s*** out of me so many times. It was like four months of learning how to wrestle," said Ruffalo.
However, Ruffalo jokingly added the task was made easier by Tatum out-wrestling him over their months of training, where Tatum had a significant size advantage. He said, "He like has 30 pounds on me, so when it came time to smack the s*** out of him, I was like, 'Came from Alabama.'"
Tatum first mentioned injuring his ear during the Cannes Film Festival in 2014 while promoting Foxcatcher. His willingness to commit fully led to Ruffalo earnestly slapping him as requested.