Wolves goalkeeper Wayne Hennessey has suffered a setback in his return from injury and may require further surgery.
The Welsh international damaged the knee in training on Monday and MRI scans have confirmed that he could need another operation.
Hennessey had played in three reserve team matches and had been training fully for a month prior to the injury, having initially been ruled out after landing awkwardly in the Premier League draw at Sunderland in the spring.
Wolves' head of medical Phil Hayward said: "Of all of the players to have had such a surgery, Wayne has to have been one of the least likely to sustain a re-injury.
"His application over the last seven months has been exceptional and this was demonstrated by the fact he returned to play with such a strong and well-controlled knee.
"It is difficult to find an explanation as to why the injury occurred as he had met all of the functional benchmarks set and the surgeon was delighted with him.
"With such a surgery, there is clearly a small percentage failure rate and it would appear he has found himself amongst this unlucky few.
"The main focus now has to be on planning the next step for him, which is something that will start immediately.
"With Wayne's exceptional work ethic and the support of the medical team here at Wolves, there is no reason to think he will make anything other than a complete recovery from this setback."
The news is a crushing blow but one cushioned by the fact that Wolves have Carl Ikeme fit and in decent form, with Dorus De Vries as back-up.
Hennessey said: "It's hard because the lads in physio couldn't have done more for me, I've trained hard and there were no problems in the reserve games that I played in.
"It was just one of those freak things that can happen and it's no use dwelling on it - nothing is going to change things. So I'm just concentrating on getting fit again - I've done it once and I'll do it again."