Rooney - who has been the subject of two unsuccessful bids from Chelsea - briefly visited United's Carrington training ground on Tuesday, having not travelled to Sweden for their friendly against AIK Solna due to a shoulder injury.
The former Everton star has two years left on his current deal at United and is reportedly ready to force a transfer through by handing in a written request.
United legend Macari told Sky Sports News: "Wayne's situation, whether he's going to be at Manchester United or somewhere else come the start of the season, is becoming more and more difficult for him.
"Manchester United fans are patient. They want the best players there and there's no doubt that Wayne, over the time he's been at the club, has been one of the greatest because his goal-scoring record tells you that.
"And one of the greatest should be remembered as a great Manchester United player, but as time goes on people are losing patience.
"For somebody who should go down in history as being one of our best players ever, I'm not really too sure of the public opinion at this moment in time among the United supporters.
"I don't know what difference that makes, actually putting in a transfer request. Everyone at this moment in time is guessing whether he wants to go or not and I think it's quite simple.
"If you want to go, come out and say 'I want to leave Manchester United', and if you want to stay come out and say 'I want to stay'.
"But we hear nothing, not just from Wayne but from all the players nowadays."
