Manager Terry Connor revealed early on Tuesday that the 25-year-old was awaiting scan results after complaining of a problem during last weekend's 0-0 draw with Sunderland.

Hennessey decided to play on during the match despite the injury and Wolves have now announced the Wales international is unlikely to feature again in 2012.

Steve Kemp, head of medical service at Wolves, outlined Hennessey's situation:"Our worst fears have been realised, Wayne has ruptured his anterior cruciate ligament and will have surgery this afternoon.

"He will be out for around six months."

The news comes as a further blow to interim boss Connor, who is already facing the prospect of relegation with the Midlands club.

Dorus de Vries is now expected to make his Premier League debut when Wolves host title-chasers Manchester City on Sunday.

The Dutchman joined the club last season on a free transfer from Swansea City, but has only made five appearances, all in cup competitions to date.

Wolves have also taken action to strengthen their goalkeeping options by recalling on-loan goalkeeper Carl Ikeme from Doncaster Rovers, with Connor claiming: "We felt it prudent to recall Carl as a precaution because, whatever happens, the initial scan shows that Wayne would be doubtful for the weekend.

"But we will have to wait until he has seen the specialist before we know the full extent of his injuries."