McGleish, 35, and his strike partner James Scowcroft, 33, are seen as the elder statesmen in an otherwise relatively youthful O's squad.
But McGleish insists the talent is in place to drag Orient away from the wrong end of League One.
"I think we've got to believe in ourselves a bit more," he said.
"We can play football, we have seen that, but apart from me and Scowie we're a very young squad, especially the boys on the bench.
"They're very good, we see it every day in training, but when they go out there they've got to replicate what they do in training. They've got to believe in themselves."