LONDON -- David Beckham will find his latest mission of transforming soccer in America more difficult than expected, according to the manager of his former team in England. Beckham is attempting to turn soccer into a mainstream sport in the United States after joining the Los Angeles Galaxy with a five-year, $32.5 million contract in July. However, ankle and knee injuries have restricted him to a frustrating 306 minutes of play. Even a fully fit Beckham would be unable to overcome the problems the sport faces in the United States, Manchester United manager Alex Ferguson said. "It is difficult with David going there. I don't know what kind of impact he can make,'' Ferguson said Tuesday to an audience at the Citizens Theatre in Glasgow. "David Beckham himself can't change the whole country.'' Ferguson said the size of the U.S. prevents the intense rivalries between fans that he feels make soccer exciting. "In European soccer, and especially in British soccer, you can travel easily,'' Ferguson said. "If you are in Boston and need to go to Los Angeles, it's a six-hour flight. Supporters don't travel, so you are missing that rivalry between fans. "To make it substantial you would have to go regional, but there's not enough teams to have four strong leagues.'' Ferguson said Major League Soccer is undermined by young American players leaving for European leagues early in their careers. "What you have got in the States is that a lot of kids are playing football in the States and there is nowhere to go,'' he said. "The best American players go to Europe very early, like Brad Friedel [at Blackburn], [Brian] McBride and [Clint] Dempsey at Fulham. That situation doesn't help the American game.'' Ferguson coached Beckham throughout the England midfielder's 11-year stay at United, but their relationship later deteriorated. "He was never a problem until he got married,'' Ferguson said. "He was a fantastic young lad. Getting married into that entertainment scene was a difficult thing -- from that moment his life was never going to be the same. "He is such a big celebrity, soccer is only a small part. The big part is his persona.''