Aaron Wan-Bissaka
The young Englishman has burst onto the scene with Crystal Palace this season and is now one of the most sought after players in English football. United are lacking in the right back department with Antonio Valencia ageing. Diogo Dalot is beginning to look like a solid player himself but there is no doubt that United need to add to their right back options.
Joao Cancelo
With Wan-Bissaka so highly sought after, it may actually be easier in this instance to go shopping in Europe. Cancelo has been highly impressive for Juventus this season, and was only signed last season from Valencia for 40 million Euros. He does have Champions League experience however, potentially making him a more attractive option.
Saul
It is rumoured that Saul is fed up at Atletico and in particular with manager Diego Simeone. It seems very likely that Saul will find himself in the middle of a battle between the Manchester clubs to sign him. After Jose Mourinho signed Fred in the summer, (a deal which has not worked) United need to bring in some midfield talent and Saul is believed to be a perfect option.
Ivan Rakitic
His days at barcelona now seem numbered after Barcelona spent big money on Frenkie de Jong joining the club in the summer. Sources close to the club have indicated that de Jong will fit straight into the Barça midfield, allowing for Rakitic to become available. He is now 31, meaning he may come slightly cheaper than his counterparts on this list.
Marco Verratti
Perhaps the most ambitious potential signing on this list, Verratti is one of Europe's top midfielders and it doesn't appear that he will be leaving PSG anytime soon. It would therefore be a big transfer, but if United could persude PSG to part with the Italian, it would be a major signing.
Toni Kroos
Kroos has been linked with Manchester United for many years now, and very nearly joined them in 2013, under David Moyes. However, instead of wearing the jersey of the red devils, he has been wearing the white one of Real Madrid, where he has excelled. However, now it seems that Madrid could be looking to sell the German as Zinedine Zidane looks to majorly rebuild his squad.