Former Arsenal captain Gilberto Silva admits Fred has joined Manchester United at a difficult time.

Gilberto acted as Fred's agent during his move to United last summer.

In the Manchester derby a week ago, they were outplayed by City in a 3-1 defeat.

"The moment at the club is not the best," he said. "That has been a problem. And that means there has been a lot of pressure on him and the rest of the players.

"Also, Fred has been used to playing in a certain system in the Ukraine and now he has to get used to another one.

"But I know him well. I know he will fight. When I speak to him he tells me he just wants to work harder. He is very determined to be a success.

"And I am sure he will be."