The 30-year-old centre-back has fallen down the pecking order under Erik ten Hag and last season Maguire only managed 16 Premier League appearances for Manchester United, starting only eight of them.
Ten Hag has stripped Maguire of the Red Devils captaincy role and it is said Manchester United are willing to let the English international leave this summer to generate funds.
Rooney believes that Ten Hag stripping Maguire of captaincy indicates that the Dutchman has no faith in him and pointed out that the current predicament leaves the centre-back in a stage where he needs to rethink his future.
The ex-Manchester United star also thinks that the best thing Maguire can do in the situation is seek a move away from Old Trafford this summer to rediscover his form.
“To have the armband taken off you, how does he move forward with the club?”, Rooney told The Athletic.
“That shows the manager really doesn’t believe in him.
“It leaves Harry in a position where he has to think on what he does moving forward.
“The manager has shown he is not part of the plans.
“I’m sure Harry will want to go and play — for himself, for his England career — to put himself in the best position to be as successful as he can.
“The best thing now is probably for him to move.”
Maguire has been linked with a move to West Ham United this summer, but the Hammers have yet to make an official approach for the player.