#1. Abdoulaye Doucoure

The final player on the list is Watford’s midfield general Doucoure. He’s Watford’s player of the season and as things are, he looks he’ll keep the title again this season.
He’s energetic, strong on the tackle, gets up and down the field quite easily and top it up he has goals in him. The Frenchman can surely be a perfect fit to replace Ander Herrera if he does leave the club.
He’ll offer passion and no-nonsense style of play in that midfield while also keeping things ticking just what Herrera has been doing. Of course, Watford will demand a huge fee for him, but of all players on this list, he’s probably the one that may come cheap for United.
Even if none of the midfielders does leave United, Doucoure will provide great cover for the team and may well even end up challenging for a starting position in the long run.