Manchester United legend Paul Parker has revealed a "big worry" about summer signing Matheus Cunha. He arrived at Old Trafford with a price tag large enough to command immediate attention and expectations. However, only a few months on from his £62.5 million move from Wolves, the Brazilian forward finds himself with only a single Premier League goal to his name, which came during October’s frenetic 4-2 victory over Brighton.Cunha's rhythm has been disrupted repeatedly, including by a head injury that ruled him out of recent fixtures against Crystal Palace and Everton. It was the second time since relocating to Manchester that he was forced to pause his progress. Despite the interruptions, Cunha’s most recent outing provided encouragement. Facing his former teammates from Wolves, he produced one of his sharpest performances in a United shirt. It was from his incisive work in the final third that Bruno Fernandes swept home United’s opening goal. This display has been seized upon by those who remain convinced that Cunha’s contribution goes far beyond his goal statistics. And among his admirers is former United defender Parker.Parker believes Cunha brings an edge and urgency that United have long lacked. Speaking about the 25-year-old’s influence, he offered glowing approval of the Brazilian’s work rate and mindset.In an interview with MyBettingSites.co.uk, he said: "Cunha has done very well. He is very unselfish in everything he does. He never stops running, and sometimes he might even do too much, but that is just the way he is. His teammates need him and the team needs a player like him, because he gets the other people going. It affects his teammates a lot when he is not playing, so I really think he is important to the team."Parker went on to compare Cunha to another United icon, while insisting that his performances at Wolves last season demonstrated a level of quality that always appeared too elevated for a struggling side.He added: "His attitude is great and he never gives up. Man United haven’t had a player like him for a long, long time. He is a bit like Park [Ji-sung] in a way, but quicker. He has made a massive difference. He did amazingly for Wolves and he was too good to be in that team."Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!But alongside his admiration, Parker also issued a warning, one which is rooted not in Cunha’s ability, but in the nature of his personality. He suggested that players who operate with such wholehearted commitment often expect the same from those around them, a dynamic that can become troublesome if teammates fall short of that standard.He said: "But I am worried about what he thinks about his teammates, because players like him who give everything, they can be very unhappy if his teammates are not good enough. That is a big worry, because I think he is demanding a lot. But in almost every other team, it would never be a worry. It is a very positive sign, but at Man United, with the players he is surrounded by, it can become an issue."The mood around Old Trafford has improved following the recent victory over Wolves, a result that lifted United to within a single point of fourth-placed Crystal Palace. Head coach Ruben Amorim will know that momentum, something United have struggled to sustain, must now be preserved with another victory over Bournemouth next Monday.