The tourists, chasing a victory target of 299, crumbled from 109-0 to 224 all out as they lost the fourth Test to go 3-0 down in the best-of-five series.
Asked if careers were in jeopardy, Lehmann said: “Yep, there’s nothing wrong with that.
“The blokes have to learn. If they don’t, we’ll find blokes that will.”
Lehmann replaced Mickey Arthur just 16 days before the Ashes series got under way, but he has failed to engineer a turnaround in the side’s form following the 4-0 Test series defeat in India earlier this year.
Australia lost the first two Tests of this series at Trent Bridge and Lord’s respectively but had a chance of reducing the deficit in Durham.
Chris Rogers and David Warner put on a century opening partnership in their second innings to give them hope of reaching the 299 victory target.
But Usman Khawaja, Michael Clarke, Steven Smith, Shane Watson and Brad Haddin mustered just 50 runs between them as Australia capitulated.
England now hold an unassailable 3-0 lead heading to the fifth and final Test, which starts at The Oval on Wednesday, 21 August.
Australia’s misfiring batting line-up has only passed 300 once in eight innings during the Ashes series.
Watson, Khawaja, Smith, Ed Cowan and Phil Hughes have all struggled for runs during the series and Lehmann appears to be losing patience.
“To play for Australia, you’ve got to perform at a level that is acceptable for everyone in our team and also for the Australian public and the media,” he said.
“At the moment, we’re not doing that, so blokes have got to perform at a level we expect.
“We’ve lost clumps of wickets which have really hurt us. Blokes are missing straight ones, that doesn’t help.
“We have to learn from our mistakes. We didn’t learn from probably Trent Bridge when we got bowled out in similar circumstances, so, from our point of view, the blokes have got to learn.”
Lehmann said he had been confident of victory in Durham following a great start to Australia’s second innings but said some of the shot selection had been “poor”.
“That really hurts, that one,” he said. “They bowled well, we batted really badly in the middle order, lower order.
“I thought Warner got a good ball to be fair, Clarke got a ripper and Rogers probably got a decent ball. The rest should have played a lot straighter and they know that.” Clarke and Rogers are the only specialist Australian batsman to score centuries in 2013 and Lehmann said only those two were probably “guaranteed” their place in the team.