Derek Geary was pleased to see his youngsters progress to the fourth round of the FA Youth Cup, following Tuesday 2-0 victory over Burton Albion at Bramall Lane.
Jordan Doherty scored a second-half brace which was enough to beat the Brewers and set up a meeting at Birmingham City in the next round.
Geary was happy to win the tie, but acknowledged his side were far from their best on the night.
He remarked: "Because I know the talent these players have I'm still a little disappointed they haven't got the best out of themselves.
"It's more of a compliment really when you beat a fellow Championship side 2-0 and I'm still a little disappointed.
"Credit to the players that they did enough to win the game and we showed the quality we have in the second half."
The U18s chief added: "We've been working on getting Doherty in behind the striker all week and he is a talented boy so we knew if we could get the ball into him he has those strikes in his locker.
"Bravery comes in two different forms, when you're under pressure to stay in the game and you need to show bravery on the ball and want it more.
"We'll need that to continue in this tournament and I believe we showed both qualities in the second half."