The Social Network star hurt his left calf muscle while on on the set of his upcoming movie Now.
Justin will get back working today alongside co-stars Amanda Seyfried and Cillian Murphy, following a week's hiatus.
Just days after he sustained the injury, the 29-year-old told Etonline.com: 'It'll be fine. It's not irreversibly damaged... I was just on set and I hurt it. I wish I had a way better story about how I got into this Bruce Lee, Kung Fu fight with someone and 'you should see the other guy,' but unfortunately I did it to myself.'
The thriller Now is set to hit cinemas some time next year.