The Dutchman told the Daily Mail: "For a start, they play in the summer and that means it can be 90 degrees and 80 per cent humidity. You just can't play high-tempo football. Certainly nothing like the Barclays Premier League, which is all about long ball and pace.
"Then there's the travelling. If you're in LA and you've got a game in New York you're talking about a six-or-seven-hour flight.
"I'd liken it more to the leagues in Holland, Belgium and Norway. The players can play. I watched the All Stars against West Ham in the summer and the All Stars outplayed them. And I think Beckham has already proved he can do it. His crossing and dead ball delivery is still important to England. Sometimes decisive."
Certain aspects of U.S. soccer frustrate him: the failure to arrange fixtures around the international calendar; the draft system that prevents clubs from building a youth development structure; the salary cap that denied him the chance to lure European players to America.
"We could have a game the day after a round of international matches, that was ridiculous and so was the draft system. I could have players I wanted to promote from the under 21s but they were no use to me because they weren't actually mine, they could go into the draft system and end up elsewhere. It all became very frustrating and it has to change."