Russell Slade revealed his disappointment with Orient’s marking after an injury time Jon Obika goal saw them held to a 2-2 draw with Yeovil Town.
Kevin Lisbie’s first half header put the home side in control at the break before the O’s top scorer doubled the advantage from Jamal Campbell-Ryce’s cross.
But with eight minutes remaining, the Glovers began their revival as first Andrew Williams tapped in from close range before Obika was on hand at the back post to head in late on.
It was a point which ensured the visitors will be playing League One football next season, but Slade felt it was a “poor goal to concede”.
“We have not dealt with two long balls. There were a lot of long balls we had to deal with all afternoon from a very direct Yeovil side. Unfortunately there are two occasions where we have not dealt with either the first phase or the second phase,” he explained.
“We have just not marked well enough from the second phase. We have marked from the first one and we have actually won the ball from the first one. But in the second phase, we have been a bit naïve and we have not picked up.
“It wasn’t good enough. It is a poor goal to concede. We should have been throwing bodies on the line. We should have been marking people at a crucial time in the game.”
He added: “I thought it was a good, professional performance up until then. Unfortunately at this moment in time, we don’t seem to be able to keep the ball out of the net.”
With the contest entering injury time, Slade brought off Campbell-Ryce and Sunderland loanee Adam Reed, and the manager explained that injuries forced his hand at that point.
He continued: “Jamal had to come off – he was injured - and Reedy had picked up a knock as well, he was struggling a little bit.
“It was just fatigue and injuries really that made me make the substitutions. There was no tactical reason to do that other than that two of the boys were struggling a little bit.”
The O’s were desperately close to securing maximum points and Slade was thankful to the “fantastic” support from the home crowd during the match.
He added: “It was fantastic. The support was good all afternoon to be honest. It just looked like we had given them the performance that everybody desired but unfortunately we let it slip in the dying minutes.”