Manchester United boss Sir Alex Ferguson admits Nemanja Vidic has become a cornerstone of his team.

performance last weekend against Everton at Goodison Park. He followed it up with another commanding display at Sporting Lisbon on Wednesday, prompting praise from his manager.

"Nemanja always asks a question of defenders," Ferguson told manutd.com. "He wants to know whether they have the courage to put their head in front of his.

"He is a throw back to the old style of defender, but there's no question he can play, there is not a doubt about that. He doesn't mess about in terms of clearing the ball. He acts like a defender and that's a real asset to this squad."

"He got me four goals last season and has already got one this year," said Ferguson. "I think he can easily get between five and 10 because he has got just the right qualities."