Van de Beek arrived from Ajax amid plenty of fanfare ahead of the 2020-2021 season but the Netherlands international has continued to be overlooked by United manager Ole Gunnar Solskjaer.

The 24-year-old has been an unused substitute in United's opening two Premier League games of the 2021-2022 campaign, having made just four starts in the league last term.

Van de Beek's agent Guido Albers said the Dutchman has been given "clarity" over his United future by Solskjaer, who insisted the former Ajax star is an "important" part of his plans.

Berbatov – who won two Premier League titles among other honours during his time at United – believes Van de Beek should leave Old Trafford if he is unhappy.

"The transfer window closes on Tuesday and, while United have done well to bring in some good players, I still think there may be some action to come with outgoings," Berbatov wrote in his Betfair column. "I don't think we're going to see any more playing time from Donny van de Beek.

"It's a really strange, disappointing and surprising situation. They spent around £35million on him and, to pay that for a player who isn't starting many games, doesn't make sense. I'm not blaming the player at all, but for me it's one of the most disappointing transfers ever."

United won three and lost one of the four games Van de Beek started in the league last season for a 75 per cent win rate.

That drops to 52.9 per cent in the other 34 matches the Red Devils started without the Dutchman, while their average goals scored fell from 2.3 with Van de Beek to 1.9 without.

Van de Beek led the way for United in the Premier League in 2020-2021 in terms of tackles won per 90 minutes (1.75), meanwhile, and Paul Pogba (2.09) was the only midfielder to play more than once to complete more dribbles per 90 minutes than Van de Beek's 1.4.

"He has got a lot of quality," Berbatov said. "I don't like it when clubs buy for the sake of buying and this is one of those situations. I'm sure he's banging on the manager's door and asking questions.

"I think if he's not happy, Van de Beek should push to leave. His place in the national team is at risk, especially now with Louis van Gaal in charge. Van Gaal is a disciplinarian who like his players to play football.

"Paul Pogba and Bruno Fernandes are untouchable in the United midfield at the moment. Scott McTominay, Fred and even 33-year-old Nemanja Matic are ahead of van de Beek.

"I know how Van de Beek feels. In the late stage of my career I was playing in Greece, the president wanted me and signed me, but the coach didn't want me and we had some issues. It is frustrating for a player. He needs to have a long hard think about his situation and what he wants."