Oxford's first-team coach Andy Melville could take positives from Oxford's 2-1 Johnstone's Paint Trophy loss to Portsmouth.
Patrick Agyemang's brilliant goal opened the scoring and John Marquis added a second before James Constable scored a consolation goal in the 89th minute and Melville felt there were a lot of good things to take out of the 2-1 loss.
Melville said: "There were plenty of positives from the first half, there was a lot of desire, good front-foot football from us, and we kept getting in behind them, and we mixed our game up well.
"The first 15 minutes of the second half we started OK too. Then they brought Agyemang on and that changed the match. He caused us a lot of problems.
"He got a goal out of nothing and it was a great finish, the best bit of quality in the game.
"It was a decent ball in from their right-back and a great header for the second goal.
"But for our young lads it was a really positive night for them. They can hold their heads up high.
"It's a bit disappointing we lost the game but we felt the young players' performances were really positive for us."