He said: "When you talk about Manchester United you are talking about a top side spending big, big money on every single player. Every season.
"For me that is the main difference between the teams. You have seen that with regard to Chelsea before, spending big money.
"The advantage United have is that they have a big squad, in the last years they have spent money to improve that squad even more.
"We cannot do something like that. We spend too much time worrying about whether Steven Gerrard and Fernando Torres can play while they can play Ronaldo, Carlos Tevez, Berbatov or Wayne Rooney, it doesn't matter to them."