United hosted Doncaster Rovers on Saturday afternoon in the third of their Youth Alliance Cup group fixtures.
Rovers took the points with a first half goal which proved to be enough to ensure that the young Blues will not progress in the competition, despite still having one group game to come.
Academy boss Eric Kinder said: "It was very frustrating because it's another game where we dominated but we just didn't convert the good play we had into goals.
"Having controlled much of it we made a mistake in the first half, we were punished, and then we just didn't look like scoring.
"The new striker we signed - Ethan Henderson - was ruled out with an injury and you could tell that we missed him. We tried different combinations, with Barnes, Rooks and Swailes all playing up front at different points during the game, but the ability to get the ball into the net was lacking.
"We know we're out of that competition now and that's a shame because we've played well in all three group games."
More details to follow.