Manchester United have joined Liverpool and Arsenal in making enquiries for an ambitious Premier League midfielder, according to reports.Just a few days remain before the end of the transfer window, but the big clubs are all still busy. Man Utd have strengthened their squad with the signings of Jadon Sancho and Raphael Varane this summer. But they still have some outstanding tasks on the agenda. They have been considering other areas of their squad to strengthen all summer.Right-back was one area they looked at, although they seem to have put any pursuits there on the backburner. Likewise, they were able to delay their centre-forward hunt when Edinson Cavani renewed his contract.Instead, reports have been indicating for a while that the next area United could look to bolster is midfield. Doubts currently linger about the future of Paul Pogba, who has started the season in fine form despite there being a risk of it being his last in the red shirt.Even if Pogba stays, it may help to find another midfielder to play in the deeper pairing. That territory is usually occupied by Scott McTominay and Fred, but it could be somewhere to upgrade.Subscribe for free to TEAMtalk’s daily newsletter…In that regard, a recent report suggested there were three names on their shortlist: Eduardo Camavinga, Saul Niguez and Ruben Neves. However, Chelsea look more likely to sign Saul at present. United’s reinforcement – if they get one – might actually be a fourth name instead.According to Duncan Castles, Man Utd have made an enquiry about Brighton midfielder Yves Bissouma.Bissouma joined Brighton from Lille in 2018 and has impressed ever since. He has frequently been mentioned as a potential target for clubs of European stature. For example, when Graham Potter recently addressed his future, links with Liverpool and Tottenham were the most prominent.Indeed, Castles confirms that Liverpool have also made a similar move, as have long-term admirers Arsenal. But Man Utd have entered the fray as well.Castles said on the Transfer Window Podcast: “Along with those players we mentioned as options for Manchester United’s midfield, Bissouma is also being looked at by them.“They know Bissouma has two years left of contract at Brighton and is keen to move to a higher-status club, keen to play European football.“My information is that there are enquiries from Liverpool, United and Arsenal as to how much it would cost to sign him.”However, the answer to those enquiries may not have been what the interested parties were hoping to hear. Although Bissouma’s contract situation means his value may begin to decrease, Brighton are under no immediate pressure to sell.Castles added: “I think with Bissouma, it’s become a bit more complicated for the clubs bidding for him because Brighton are cash rich at the moment after the sale of Ben White and they do not need to take the money in order to reinvest it in the areas which they are targeting, which are centre-forward and left-back.“I understand they’ve opened discussions with Bissouma about improving his salary and extending his contract with the idea of retaining him for at least one more season.”Therefore, the chances of him following ex-teammate White to Arsenal, or moving north to Manchester or Liverpool, are still in doubt.Links with Liverpool have been ongoing ever since their release of Georginio Wijnaldum. Arsenal, meanwhile, have added Albert Sambi Lokonga to their midfield, but could use another reinforcement.READ MORE: Donny van de Beek makes decisive call on future as Man Utd agenda is set