The movie - released in limited US cinemas on February 17 - follows the lives of young student athletes and their coach, who battle their way through the American football season in northern Memphis.
He said in a release: "I am excited to partner with Harvey Weinstein on this incredible project. Undefeated is a great American story with a lot of heart and soul.
"It had a profound effect on me and I couldn't get it out of my mind when I saw it. There is so much truth and so much hope in this film, and I feel passionately that everyone who sees it will be inspired."
The rap mogul was also credited as a producer on the original documentary.
Diddy, Rihanna, Pamela Anderson and LL Cool J will all attend a post-Grammys party at the Playboy Mansion in Hollywood on Sunday night, where a host of stars will help raise money for the Angelwish Foundation.
Playboy boss Hugh Hefner will be honoured with the 'Humanitarian of the Year' award by the organisation, following the 54th annual music ceremony.