Harry Maguire is said to be monitored by Milan these days. This must be great news for Manchester United to get rid of him easier. 
Honestly him and Lindelof have been really inadequate in the defense line so far. Varane and Martinez's absence has been felt very much because of this situation.
Manchester United can surely find a better defender than Maguire to do a good job when there is a need. Their defending has been horrible recently. I wonder why Milan are interested in him as well. Maybe they would think of him as a backup defender if he doesn't perform well there too.
Sometimes there are also players who move to a club, instead of playing worse, they get better, if there is a player like that, for example Maguire, if he can play well at Milan, it means that all this time it is not Maguire who has played completely bad, but perhaps his positioning or other things have made him he played badly at manchester united, but we don't all know what milan wants for a player like Maguire. Honestly him and Lindelof have been really inadequate in the defense line so far. Varane and Martinez's absence has been felt very much because of this situation.Manchester United can surely find a better defender than Maguire to do a good job when there is a need. Their defending has been horrible recently. I wonder why Milan are interested in him as well. Maybe they would think of him as a backup defender if he doesn't perform well there too.
I think if Manchester United let him go, at least they could look for a replacement who is better and experienced enough in the back line to strengthen their back line well, so far their game has not been good at the back so they really have to improve overall to pay for everything. the defeat suffered by Manchester United in the last few matches.