Over the space of a few months, the 18-year-old has become a vital player for the Red Devils, while he debuted for England during the March international break.
Mainoo's first appearance for England came off the bench against Brazil last weekend before being handed his first start for the Three Lions against Belgium on Tuesday night.
The midfielder is now seemingly in line to be selected in Gareth Southgate's squad for Euro 2024 and will remain a key player for his club in the latter stages of the campaign providing that he is fit and available.
Ten Hag has lavished praise on his England performances and also insisted that the teenager will keep his feet on the ground amid the noise surrounding him.
«I thought it was very good [display for England] but we are not surprised. We know what he is capable of, he can very quickly adapt to high levels. It looks very natural and we are very happy for him,» Ten Hag told reporters during his press conference on Friday.
«Of course, we are also very [proud], it's great for the academy of Manchester United to bring up a player so young going into the national team, it's a big compliment for the whole club.
»For himself because he did it but also all the ones who worked with him during his time in the academy, it's very good news for Manchester United.
«Yes but we have discussed this before. So far, he handles it very well and if he crosses the line, of course, I as a manager, we as coaches, will interfere.
»But so far it is not necessary because he wants to play football, he wants to win, he wants to give his best every day
Read on sportsmole.co.uk