Jack Whitehall dislocated his ribs while training with Dwayne 'The Rock' Johnson.
The 29-year-old comedian is currently starring alongside the semi-retired professional wrestler in Disney's forthcoming movie 'Jungle Cruise', but he was left red faced this week when he agreed to workout with the 46-year-old star and managed to disjoint his ribs - which can cause back pain and trouble breathing - on an exercise bike.
Taking to his Instagram account, the funny man uploaded a photograph of The Rock lifting some heavy weights in the gym while he's lying on a massage stretcher.
He accompanied the shot with the caption: "So billy big b******s @therock is in his gym pumping copious amounts of Iron for fun. I pop on an exercise bike for twenty minutes and end up in Hospital with a dislocated rib. Doctor asked if I was in an unnatural position. Indeed - the TV monitor had the movie 50 First Dates on and I was craning forward to read the subtitles. X-Ray, two shots, trip to a chiropractor and a sports massage later and it looks like I will survive. (sic)."
'Jungle Cruise' is based on the Disneyland theme park ride of the same name, in which passengers board a small riverboat which takes them through a jungle filled with dangerous animals.
The movie version is set to have a supernatural element, and will be set in the Amazon jungle during the 20th Century.
The Rock, who was the first name attached to the project, will play the boat captain who takes two siblings - played by Jack and Emily Blunt - on a dangerous, yet thrilling, mission to find a tree believed to possess healing powers.
Last month, Jack confirmed his involvement in the film and admitted he was "so excited" to be joining one of his "heroes" in the motion picture.
He tweeted: "So excited to be joining Jungle Crusie with the incredible Emily Blunt and one of my heroes @TheRock going to be a blast. #Disney #JungleCruise (sic)"
Tagged in Emily Blunt The Rock Jack Whitehall