Paul Simpson hopes the injury that cut short Jack Diamond's full Carlisle United debut isn't serious.
The Sunderland loan winger limped off in the 20th minute with an ankle problem.
It compounded another bad day for the Blues as their 3-2 defeat sent them bottom of League One.
Diamond will be assessed in the hope he will not be forced onto the sidelines.
"I think it was just a kick, but it’s too early to say," said United's manager Simpson.
"We’ll asses it on Monday and see how it settles down but I’d like to think it’s nothing serious.
"He got a whack on [his ankle] and it was too sore to carry on. He didn't feel stable enough on it."
Simpson, though, conceded that Carlisle could not pin all their hopes in Diamond's fitness and hoped-for creative influence.
"There are many things we need to do better and need to improve on rather than hoping and praying that Jack Diamond is right," said the manager after the fifth straight defeat.
"We’ve got to make sure we do a lot of things better than we did today."
Simpson did not hide from the seriousness of Carlisle's predicament after their latest setback in east London.
They remain ten points adrift of safety with 16 games to go after another poor showing.
"We’ve got to be a bit more streetwise and learn to do the things that [Orient] have done that have kept them with a foothold in the game," Simpson added.
"We’re disappointed. We knew this was always going to be a tough game but the truth of it is we’re in serious trouble and this was a day we needed to start getting wins.
"We were in trouble before today and we’re still in trouble now. There’s still a ten point gap but like I keep saying, if we don’t start winning games then it’s irrelevant what everybody else does.
"We have to just roll our sleeves up and play with a bit of pride. We’ll keep working and see what comes."
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