He told the Sunday Mirror: "The way Ferdinand and Vidic play is very similar to the way Steve and I went about things. Rio has always been a top-quality footballer, but I think bringing Nemanja in to play alongside him has seen his play go up another notch.
"It took a while for the partnership to develop, but now we are seeing the value of two lads playing together week in, week out. It doesn't matter whether you are two strikers trying to develop an understanding or two centre-halves. You only get better with time and experience.
"Rio is now looking every inch the player people thought he would become when he broke into the West Ham team at a very early age - and I think a lot of that is down to Vidic.
"I don't think I've ever seen a player who attacks the ball with as much commitment as Nemanja - in both penalty areas.
"He is so competitive that it looks like he is ready to kill anyone who goes near him! That's why the fans love him so much and why United have just handed him a new contract."