Caporegime
When I saw the reports that Utd were now not willing to let Maguire go, I assumed it was just a negotiating tactic and they were just making it clear to Maguire that they won't be paying him £10m+ to leave however this is probably why.
I think somebody on here touched on it when he announced his retirement from international football but it seems like his body is shot and he can't handle playing regularly anymore.
I think its a bit of everything. When we didn't want to sell him Varane wasn't injured, Shaw wasn't injured and Maguire was 5th in the pecking order. Now we have Varane and Shaw injured he is 3rd in line. Martinez seems to be having a bit of a shocking start to the season as well.
If someone came in and offered what we wanted and Maguire was willing to go quietly I have little doubt he would have gone. I think we would have brought in another CB to replace him though.