The British star insists he is grateful for the success of the hit film, but admits he has struggled to find more challenging roles since appearing as the all-singing, all-dancing Sky alongside Amanda Seyfried, Meryl Streep and Pierce Brosnan.
So he immediately snapped up The Devil's Double, based on the book of the same name by Latif Yahia, an Iraqi man who was forced to act as the body double of troubled Uday Hussein.
Cooper, who portrays both Yahia and Hussein in the film, tells WENN, "I'd love people to see this because it was so rewarding and I worked so hard on this and it's a low budget film. It's nice to be seen in a different light I suppose...
"Up until now, in terms of my film work, I've enjoyed doing supporting roles but it's quite problematic trying to sell yourself to get into any film you possibly can, but then you can be pigeon-holed. Being so fortunate that you end up in a musical film (Mamma Mia) that does extremely well, the opposite end of that is people think you're all-singing, dancing and that's what you do; you're a musical theatre person. I'm really thankful to have the opportunity to be able to show a different side of what I can do."