J.J. Abrams was worried Tom Cruise would be injured on the set of ' Mission Impossible III'

Tom Cruise in "Mission Impossible"

The 'Star Trek Into Darkness' director took charge for the third movie in Tom's 'Mission Impossible' franchise but admitted Tom's insistence on doing his own stunts terrified him as he was worried his star would get hurt.

J.J. told the May issue of Playboy: "There was nothing I ever asked him to do that he wouldn't do. There were things I asked him not to do because he was so willing to put himself physically in danger. I would be like, 'There's not a f***ing chance you're going through that window. If you get cut. . .'  But he was always about the better idea."

J.J. also insisted Tom, 50, is one of the most generous and professional actors he has ever worked with.
He said: "Before I started, I called Cameron Crowe, and asked him his advice, since he'd made two movies with Tom ['Jerry Maguire' and 'Vanilla Sky']. He just said, 'Brother, you are going to be spoiled.' I now know he was right. Tom is the hardest-working, most generous, passionate-about-the-form collaborator I could imagine.

"I was a first-time feature director, and before we started shooting Tom said, 'I'm your actor; you're the director.' There was not a day on that movie when Tom was not supportive, encouraging, collaborative, excited. He never mandated anything. He never insisted on things going a certain way."