Manchester United legend Paul Scholes says his former club cannot afford to lose record signing Angel Di Maria as they prepare to return to the Champions League.

Di Maria has struggled to perform at his best since his £59.7 million move from Real Madrid last summer, with Paris Saint-Germain and Bayern Munich linked with a move to pry the Argentine winger away from Old Trafford this summer.

Writing in his column for The Independent, Scholes said Di Maria needs to be given a second chance to establish himself at Old Trafford, with a return to Europe's elite competition the spur that could spark the 27-year-old back to top form.

"For £59.7m, the hope was that he would give United much more," Scholes wrote. "I accept he has had problems off the pitch settling into life in Manchester, but there is no way he can see the season as anything other than a disappointment. This was, after all, the best player in last season's Champions League final.

"Nevertheless, the quality is there and I don't think United can afford to lose him. They need that kind of player if they are to compete in the Champions League. Let's see what next season brings."

Angel Di Maria will be key for Manchester United in the Champions League next season, Paul Scholes said. Matthew Peters/Man Utd/Getty Images

Meanwhile, Scholes was less forgiving when he assessed the contribution of striker Mario Balotelli in his first season at Liverpool, as he suggested the Anfield club would be wise to off-load their less than prolific forward this summer.

"I was one of those who thought that £16m was too good a deal to turn down for an Italy international," he stated. "It is hard to make that case now. He has had a few injury problems, but most of all it has been the sulking that has been the major issue.

"He just has not fitted the way that Brendan Rodgers has wanted to play at Liverpool. Rodgers wants hard-working, quick strikers. Balotelli may be quick but there is no way he is hard working. Perhaps next season he might flourish but I don't think he'll get a second chance."

Scholes also argued that Southampton manager Ronald Koeman deserved to be Manager of the Year ahead of Chelsea boss Jose Mourinho, after he guided the Saints to a seventh-placed finish in the Premier League.