Manchester United are reportedly eyeing a surprise raid on Liverpool for the services of Alexis Mac Allister. It's been widely reported that United are seeking midfield reinforcements ahead of next season, with Casemiro due to leave when his contract expires in the summer. In an unexpected twist, they are said to be keeping tabs on Mac Allister ahead of a possible approach.

Pulling off a successful move would represent a monumental challenge for United, given the intense rivalry between the two sides. They may be forced to pay over the odds to get a deal done if Liverpool are even willing to entertain their advances at all. Alternatively, the Red Devils could try to sweeten the deal by sending one of their own players the other way.

Express Sport takes a look at three potential candidates...

Mainoo would provide Liverpool with a like-for-like replacement for Mac Allister, while having the added benefit of being younger with higher potential for growth.

However, his resurgence under Michael Carrick suggests that United would be highly unlikely to send him to Liverpool of all clubs.

Mainoo may also resist any...