The 18-year-old Dutch defender played 74 minutes of United's vital 1-0 Europa League win over Zorya Luhansk at Old Trafford which he admits pout a smile on his face.
"I feel better and better," he told MUTV.
"You always just want to play football. When you play football you just feel happy.
"I played against Northampton (in the EFL Cup), I played today and I feel happy."
Fosu-Mensah also revealed that apart from gaining an education from manager Jose Mourinho and his coaching staff, he seeks information from such players as Wayne Rooney, Michael Carrick and Zlatan Ibrahimovic to help develop his game.
"I listen to the coaches but also to the players. To Wazza, Carras, other more seniors like Zlatan," he added.
"I listen to them a lot and they help me to develop into a better player."