Mainoo's breakthrough season with the Red Devils, which included scoring the winning goal in an FA Cup final win over English champions Manchester City, earned him a call-up to Gareth Southgate's squad for Euro 2024.

Despite winning a second trophy in two seasons at Old Trafford, Ten Hag's future remained in doubt after United finished eighth in the Premier League.

However, Ten Hag confirmed on Sunday he has been told by the club he will remain in charge next season.

"Happy to be building with him, he's already got two trophies and hopefully there is more to come," Mainoo told reporters at England's training camp on Tuesday.

"It's nice to have that piece of mind. We know what manager we are going back to.

"He put so much trust in me and belief in me. I can't thank him enough."

Mainoo came off the bench late on in England's 1-0 win over Serbia on Sunday to make his competitive debut for Southgate's team.

England next face Denmark in Frankfurt on Thursday and Mainoo is looking forward to facing two of his Manchester United team-mates, Rasmus Hojlund and Christian Eriksen.

Eriksen scored in the Danes' 1-1 draw with Slovenia in their opening game, three years on from suffering a cardiac arrest on the field during Euro 2020.

"Me and Ramsus are both young and we are quite close," added Mainoo.

"Christian, I've learned a lot from him. The journey he's been on since the last Euros has been amazing. If I am to play on Thursday I'll need to put all that aside."