Dave Franco nearly messed up his health on the set of '6 Balloons'.

Dave Franco

Dave Franco

The 32-year-old actor had to have physical therapy for a few months after "f***ing up" his knee on the set of the Netflix movie.

He said: "I almost really f***ed up my health. I was running all day every day to lose weight and I ended up messing up my knee to the point that when we finished production I had to go to physical therapy for a couple of months."

Dave plays a heroin addict who has relapsed in the movie and admits slimming down for the role left him feeling "full-on depressed".

He added to Business Insider: "I was full-on depressed. I remember at one point my wife saying, 'You're not yourself, you're not fun to be around.' And I was like, 'I'm f***ing starving! What do you want from me?' But on set I also wasn't fun to be around. I wasn't really interacting with anyone. I was in the corner by myself, miserable."

Meanwhile, Dave recently starred in 'The Disaster Artist' and revealed how it finally felt like it was "the right time" to work with his brother James.

He said: "It was finally the right timing. For the first 10 or so years of my career, I just wanted to do my own thing. I wanted to make a name for myself, and as much as I love him and respect him, I just wanted it to be separate. And after a while, it's like, I feel like I'm standing on my own two feet, [so] I was like, 'I don't care what people are going to say [or] if they think I am riding his coattails.' I know that I have been true to myself. We had a really great time, have very similar sensibilities and are hoping to work on a lot more things together."