Former Manchester United assistant manager Mike Phelan believes only the pursuit of a "fresh challenge" will tempt Wayne Rooney away from Old Trafford.
Rooney had an indifferent season for the Red Devils last season, the England international forced to play a supporting role to new boy Robin van Persie.
And after reportedly asking to leave the club at the end of the season, new United manager David Moyes quickly sought to hold crunch talks with the striker.
Meanwhile, Phelan warned Rooney there was no better environment than at the Premier League champions and hoped the 27-year-old could be again talked into renewing his allegiance to the club.
"Wayne is at the greatest club you can be at," Phelan told BBC Radio 5 live. "Why would you want to jeopardise that?
"Unless you want a fresh challenge and you feel that challenge isn't being met at Manchester United.
"Every player is entitled to express a desire to want to move on. Any player can do that at any time.
"In Wayne's case, in the first instance in 2010, he took a lot of advice on that and got steered towards making that call but the manager was terrific. He talked to him and asked why would he want to leave the club?
"The press conference Sir Alex gave was a bit of a tear-jerker and it was genuine. There was an element that he'd chased this boy and paid big money. He was the boy that could change United."
However, Phelan did admit Rooney's recent troubles may force United into making a decision this summer on the player and his future at the club.
"Somewhere down the line there will be words said, there will be meetings and they will see if it's still alive and worth going for or they'll call time on it," Phelan said.
"He's come from a fresh-faced 17-year-old and has been under the spotlight for that time and he has delivered. He might have hit a blip in certain performances but he isn't the first or last player to have done that.
"You have to nurse them through it and hopefully he responds to that. Sometimes you have to crack the whip with him. Wayne has responded as well as he feels he can do for United, and what will be will be - I haven't got a clue."