Mainoo reportedly stayed patient through the tournament, even as others were used ahead of him in midfield and criticism began to grow around his body language and reaction. A minor back issue then kept him out of the third-place game against France, rounding off a summer that never really got moving.
Carrick did not dismiss that disappointment. "You want to play, so I understand," he said, acknowledging the emotional side of elite football rather than pretending selection alone should have been enough.
This is where Carrick’s intervention feels important. He has been in that territory before and framed the experience in human terms, not PR language. "All of us see from the outside the shine, the glamour, the positive side of football, but players are human beings and we all have our ups and downs. It's important to support each other," he said.
That matters for Mainoo because the next step in his development is not just tactical. It is emotional. Big-club midfielders are judged harshly, and young England players rarely get much room to process disappointment in public.
The encouraging part for United is Carrick’s update on Mainoo’s return. "He has been very good since he came back," he said, with the midfielder quickly back into pre-season work.
That is the next storyline now: not the tournament bench, but the response. If Mainoo turns frustration into edge, Manchester United may yet benefit from a summer that hurt in the moment but could harden him for the season ahead.