Brighton defender Levi Colwill played 45 minutes for the U21s as he continued his return from injury.
The defender on loan from Chelsea completed the first half as they beat Wolves 3-1.
He has not played for the first team since the 3-0 win over Liverpool.
Brighton manager Roberto De Zerbi revealed on Friday: I want to give him the possibility to play with the under-21s, to achieve the best physical condition.
For us, he will be a very important player for the rest of the season.
To have a centre-back who can play on the left and one who can on the right is a big advantage and very important."