Head of Youth on Macc defeatHead of Youth Tony Philliskirk described Latics' under-18's 2-0 defeat against Macclesfield Town in the Football League Youth Alliance, North West Conference as one of the worst in his time at the club.
"We were second best all over the pitch and it was not an Oldham Athletic performance," he said.
Philliskirk says his team was weak in defence, lacked creativity and steel in midfield and had no presence up front.
Though Latics were without six of their normal starters, Philliskirk added he was not using that as an excuse.
He said: "It was an opportunity for others to step up to the plate, but they failed to do so.
"It was a really disappointing all-round performance and an eye opener for me as coach."
Philliskirk added the only positives were the performance of schoolboy Ryan Ellison and also Haydn Foulds who came on as a substitute as he returned following a lengthy lay off.
Latics fell behind midway through the opening half to a harshly given penalty and Macc sealed victory with 15 minutes left with a goal from a set piece.
Latics' only goal attempt of the game came in the 87th minute when Jordan Bove saw his header easily saved.