T.J. Miller was worried about his wrestling scene with Jennifer Aniston in the forthcoming film 'Office Christmas Party'.

T.J. Miller

T.J. Miller

The 35-year-old actor had to fight the former 'Friends' star in the festive flick, which is set for release next week, as they play warring siblings Clay Vanstone and Carol Vanstone and lock horns over the hunk's decision to throw a bash for a client.

T.J is quoted by the Daily Star newspaper as saying: "I was wondering how that was going to go. Luckily, she went easy on me. I don't know if I would wrestle her in real life, I don't think I would win. She's quick on her feet and always hydrated. It's all that soda water."

And he certainly had every reason to be worried as the 47-year-old actress broke his ribs just minutes after meeting him on set, but he believes that was just "chemistry."

He said previously: "The second I met Jen, if I can call you Jen, she immediately put me in a headlock. And then did a very strange pile-driver move, and my rib cage was broken. So it was sort of an immediate chemistry, I thought."

The movie sees the Jennifer's CEO alter ego attempt to close down the Christmas party at the Chicago branch of her company, which is run by her sibling.

The movie featured 350 extras who were told to improvise throughout the scenes, but one pair took the instruction too far by mocking oral sex, resulting in Olivia Munn having to re-shoot part of the film.

She said recently: "We don't have much time to shoot these things. We come out and we shoot it four or five times, great, let's move on. Wait ... stop, stop, go back.

"There was a couple, they're extras, and she was up on a filing cabinet and his head was between her legs and that's what they decided to improv because they were told to do whatever they want."