Barmet manager Martin Allen says his side did not create enough chances in their 0-0 draw with Orient.
The result meant The Bees are without a win in their last four matches and they have slipped to 18th in League Two.
Allen told BBC Radio London: "I thought it was a slow start but Orient started very well. As the game grew, we got stronger and stronger.
"Second half we were the dominant team, but I don't think we created too much. We had to keep our concentration."
Barnet lost 5-1 at Portsmouth the previous weekend and then drew 2-2 with Morecambe.
"We've had a long week," added Allen. "We played well at Portsmouth but ran out of legs. Losing 5-1 hurts and hurts anyone with a brain.
"On Tuesday night against Morecambe we played very well and were very dominant.
"But we freshened it up here and brought some new players, with fresh legs into the squad."