Rooney explains why Man United 'should allow Ronaldo transfer'

And if they do, he reckons it any deal will help new boss Erik ten Hag build a team capable of challenging for the Premier League title.

Ronaldo's future is currently unclear after missing most of the Red Devils' pre-season.

Originally he stayed away from Carrington, and the club's tour to Australia and the Far East due to family reasons.

However, the player appears to be pushing for a move away from Old Trafford as he wants to play in the Champions League, not the Europa League.

A transfer, despite interest from a couple of clubs, including Atletico Madrid, doesn't appear to be on the horizon.

But Rooney reckons it's it will be for the greater good if Man United let the Portugal icon leave.

He told The Times: "It will be really interesting to see how Manchester United go this year. Under Erik ten Hag, I think they'll improve and the target has to be getting back into the top four.

"However, while Manchester City, Liverpool, Tottenham and Arsenal have strengthened and Chelsea are still bringing players in, United remain one or two signings away from having the squad to do it and so a lot depends on the last few weeks of the transfer window. United are doing everything to bring Frenkie de Jong in and they could certainly do with a midfielder. A No 9 too.

"I think United should let Cristiano Ronaldo go. It's not that Ronaldo can't play in a Ten Hag team. He can play in any team. Ronny will always score you goals. But my personal view is that United aren't ready to challenge for the title now, so the aim has to be to build a team that can win the league in the next three to four years, and you have to plan for that.

"If the reports are true that Cristiano wants to leave the club, then United should allow him to go and get a No 9 in who is going to be there for the next three or four years and really help them build a team that can be successful. Ten Hag has to be given time to do it."

And Rooney, currently manager of MLS side DC United, reckons Ten Hag is set to turn United around this season.

He added: "I was at Carrington at the start of United's pre-season, speaking to a few of the players and Steve McClaren. I know one thing Ten Hag has tried to change is the day-to-day environment, and that has been a real positive for everyone.

"When Ralf Rangnick was in charge a lot of the players found it difficult to come to terms with the lack of structure to the week and Ten Hag has addressed this.

"The thing about United is that the players are good. I just don't think they've performed the best they can and, under this new manager, there is an onus on them to go and do that now.

"Watching them last season was difficult at times. The big thing which stood out was that they did not look enough of a team. The players did not look happy on the pitch. They seemed like a bunch of individuals. Often I couldn't work out what they were trying to do in terms of game plan, or see any patterns of play. I think one of the big things you'll see from Ten Hag is him really trying to put his stamp on the playing identity."