Actor Jon Hamm is backing Indian baseball player Rinku Singh's petition to gain citizenship in the U.S. after portraying the sportsman's agent in the biographical movie Million Dollar Arm.

The Mad Men star reveals he has kept in touch with 26-year-old Singh, one of the subjects of the Disney film, and has even penned a formal message of support to U.S. immigration authorities championing his bid to make America his permanent home.

He says, "I've seen Rinku. In fact, I've written a letter sponsoring his citizenship to the States.

"I do follow his story and I do wish him the best. He's been injured - he injured his elbow pitching - so hopefully he will come back stronger from that injury and make the Majors. That would be a wonderful coda (end to his story)."

Hamm plays top agent J.B. Bernstein in the sports drama, which chronicles his discovery of Indian cricketers Singh and Dinesh Patel through a 2008 reality Tv contest and his efforts to turn them into baseball pitchers in America.

Both men went on to play for the Pittsburgh Pirates, where Singh is still signed.

Singh was portrayed onscreen by Life of Pi star Suraj Sharma, while Slumdog Millionaire actor Madhur Mittal played Patel.