#1 Gareth Bale

Real Madrid had signed Bale for a record deal in 2013. However, despite his ability, his playing time with Real Madrid in recent seasons has largely been limited by recurring injuries. There are rumours that he might leave Madrid this transfer window.
Bale is blessed with exceptional speed and a strong left foot. He is also a free-kick specialist and a long-range shooter. Having played at left-back for Tottenham, he has the ability to track back while defending.
There is also a possibility that Mourinho might sell Anthony Martial in the transfer window as he does not find a place in the starting XI and his form has fluctuated throughout the season. Hence Bale may prove to be the signing which will propel United to the top of the Premier League.
Bale will play on the right wing while Rashford and Sanchez will compete for a place on the left. Together, they will provide the pace on the wings.