It may be unlikely, but it's not impossible. Sergio Torres is a prime example. He gave up everything in his home country of Argentina to follow his passion of playing football in England. He was way over 20 at this point, and through his determination worked his way up through the lower leagues and now, at the age of 32, plays regularly for Crawley Town in league one, two leagues below the EPL.
http://en.wikipedia.org/wiki/Sergio_Torres
His story really inspirational, he even wrote a book about his experiences : http://www.amazon.co.uk/The-Sergio-Torres-Story-Factory/dp/1909178764
Moral of the story? Never give up on your dreams.