London - Wales head coach Wayne Pivac is likely to be without two key players in centre Jonathan Davies and flyhalf Rhys Patchell for his baptism of fire in next year's Six Nations.

Both are due to undergo surgery with Davies definitely out of contention for the Six Nations - which sees Wales get their campaign underway on February 1 against Italy - as he faces six months out due to a knee injury.

Davies, capped 81 times, hurt his left knee in the World Cup group game against Fiji while setting up a try.

He then sat out the quarter-final win over France.

The 31-year-old returned for the narrow semi-final loss to eventual champions South Africa and the third-place play-off thumping by New Zealand, with his knee heavily strapped.

Davies's Scarlets team-mate Patchell, who played second string to Dan Biggar at the World Cup, is to go under the knife for a shoulder injury.

The 26-year-old hurt his shoulder in the third-place clash with New Zealand and is expected to be on the sidelines for three to four months.

"Rhys Patchell and Jonathan Davies both face surgery following injuries sustained in the recent Rugby World Cup," read a joint statement from the Scarlets and the WRU.

"Rhys Patchell is expected to return to play between 12-16 weeks following a shoulder injury, whereas Jonathan Davies faces at least six months recovering from knee surgery."

Pivac, who replaced fellow New Zealander Warren Gatland at the helm after the World Cup, is already without Gareth Anscombe, who suffered a knee injury prior to the tournament.

Pivac's first match in charge is against the Barbarians, who will be coached by Gatland, in Cardiff on November 30.