Manchester United cannot keep changing their managers.

Robin van Persie says Manchester United cannot keep changing managers on a regular basis and he believes Ole Gunnar Solskjaer needs more time to prove his capable of doing the job at the Old Trafford helm.

Man United have employed four different managers (David Moyes, Louis Van Gaal, Jose Mourinho and Solskjaer) since Sir Alex Ferguson's departure in 2013 and they still haven’t won the Premier League.

However, ex-Red Devils striker reckons the constant managerial changes has not done the club any good.

"Especially after Alex Ferguson left, everyone realised that it would be tough to stick to that level that Ferguson achieved for all of those years," Van Persie, speaking courtesy of Enterprise Rent-A-Car, told Omnisport.

"I think everyone could see that. Now [David] Moyes has been there, [Louis] van Gaal, [Jose] Mourinho and Solskjaer.

"Ferguson took time to adjust and get to a certain level. I don't think that it's ideal for the club to keep changing the manager every one or two years.

"If you go for Solskjaer, go for him and give him time, that is what I think because the club needs to find some stability.”

Solskjaer’s side beat Chelsea 2-0 at Stamford Bridge on Monday night as they closed the gap on the final Champions League spot to three points.

And, Van Persie said of United’s display against the Blues: "Now they win against Chelsea and to be fair they had a good game.

"But you never know what's going to happen in the next few games. It's not consistent enough to be able to really play for the trophies.

"It is difficult because you have to compete against Liverpool, who are unbelievable and Manchester City, who are brilliant.

"Manchester City are not on the same level this year, but based on the last couple of years, they and Liverpool have been unbelievable.

"That is the level United have to go to, that is consistency, and that is the hardest thing in football because the league is tough.

"Even if you play against teams like Burnley away, teams like that are really difficult to get points against. You have to get everything right and that is a big challenge to get that consistency."