The player conceded a penalty in the game when his Manchester United team were leading by a goal to nil. David De Gea saved the penalty and Fosu-Mensah is looking to the bright side.
The Manchester United player told the club’s official website ManUtd.com:
"It was special. It's a great stadium [Wembley] and great atmosphere. It was very special to play in this stadium.
"It's been an exciting few weeks but I still have to learn a lot of things and that's what I'm trying to do. Keep learning, keep improving and try to develop as a player and train hard every day."
The versatile Dutch-born Ghanaian player lauded the partnership in the Manchester United team also saying he was ready to learn and play anywhere Louis van Gaal puts him. He also said the young players’ [Marcus Rashford, Anthony Martial and Jesse Lingard] smooth integration into the team is due to hard work.
Fosu-Mensah continued:
"Chris and Daley communicate so well with me. Everyone in the defence is great, of course David as well. He's a top goalkeeper and he saved us again on Saturday. You can see the partnership between Daley and Chris and how they express themselves, they're a great pair.
"I'm enjoying playing full-back but I'm happy to play anywhere the manager wants to put me. I just do my best and try my hardest."
"It's about confidence but I think we all try to do what we always do and just play our football," the 19-year-old said on the young players at Manchester United.
"We work hard, I work hard and I want to learn a lot. I'm open to learning a lot. I do my best and listen to the coaches and the senior players like Wayne, Carras, Chris and Daley. I listen to them all and try to do something with it.
"The senior players just help me with what I have to do on the pitch, where I have to stand sometimes and other things. It helps me a lot."