However, McClaren believes that Rooney's career would suffer should he leave Old Trafford, insisting that there aren't many clubs that the former Everton forward would see as a better alternative.
The former England manager told Sky Sports News: "Sir Alex always says there is only one way to go after Manchester United, and that's down. He's right, that's proved.
"There are only four or five clubs that you could say to leave Manchester United to go there and it could be seen as progression.
"I know Wayne Rooney and all he wants to do is play football and win, all he wants to do is win trophies. He is a winner and there is no better club to be at than Manchester United if you are a winner. He won't want to leave unless told he can leave."
Rooney has scored 14 goals in 27 appearances for Manchester United this season.