Kevin Ball challenged his players to make more of the bigger stage after the under-21s drew 1-1 against Middlesbrough on Monday night.
The Wear-Tees derby clash was played at the Stadium of Light, where Ryan Noble's opener was cancelled out by Bradley Fewster.
Noble fired his side ahead just after the break when he seized on Mikael Mandron's shot to poke home after the French striker challenged Boro goalkeeper Jayson Leutwiler.
But Fewster equalised just after coming on as a substitute to leave Ball frustrated with the overall performance.
"Put it this way, I wasn't particularly happy at half time - not with all of it but just some of it," he said.
"I felt we could do a lot better and I thought we started the second half a lot better before losing our way a little bit.
"Mika was there to challenge the keeper and get his shot off [for the goal] and we always encourage the forwards to follow in, so fair play to Ryan for that."
He added: "I just felt tonight that there were too many players tonight that reverted back into their shells when the opportunity arose for them to show everyone what they can do.
"For me that's a problem because the opportunity for them to play at the Stadium of Light is fabulous.
"I was disappointed with three or four of them, because there's more they've got to offer and have to produce those goods at places like this and not just in front of 300 people.
"Yes, it is a big ask when they are young but that's something the players have to learn to do."