The Hong Kong star has confirmed that his appearance in the movie is "more than a minor role", the Hollywood Reporter said.
"Sly had invited me to be in Expendables 2 but I was too busy filming CZ12 and couldn't make a commitment to the film. But he did extend his invitation to the third movie, which I agreed on the condition that I will be appearing as more than just a minor role with a few scenes," Chan said.
Meanwhile, Chan also revealed he might soon be reunited with Chris Tucker in a buddy comedy along the lines of the three Rush Hour films they co-starred in.
The project is tentatively titled 'Skip Tracer', according to Chan.
"The script is currently viewed by Chris Tucker. Personally, I feel that if he were to pick it up, it would be better if we turned it into Rush Hour 4 but I do think that three movies for the franchise is a perfect ending. It would be better to start a new buddy movie with someone new."