LONDON — David Beckham, unlike his friend Tom Cruise, is likely to find his latest mission truly impossible, according to Manchester United manager Alex Ferguson.

Beckham is trying to turn soccer into a mainstream sport in the United States, after joining the Los Angeles Galaxy in July on a five-year, US$32.5 million contract.

However, ankle and knee injuries have restricted him to just 306 minutes of action, and his introduction to American soccer has produced frustration, rather than revolution.

And according to Ferguson, even a fully fit Beckham would be unable to overcome the problems the sport faces in the United States.

"It is difficult with David going there. I don't know what kind of impact he can make," Ferguson said. "David Beckham himself can't change the whole country."

Ferguson said the sheer size of the US 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 also 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.