WING Alex Cuthbert has been ruled out of Wales' Six Nations campaign after suffering a knee injury that needs surgery.

The 27-year-old Lions speedster suffered the blow in Cardiff Blues’ final training session ahead of their Guinness PRO14 clash with the Cheetahs last weekend.

Cuthbert, who was hoping to put pressure on Wales wingers Steff Evans and Josh Adams, will go under the knife and be out for four to six weeks.

The winger, who won his 47th cap against Georgia in the autumn, has been released from the Six Nations squad with Warren Gatland already facing a nice back-three selection headache for Ireland a week on Saturday.

The head coach should have Leigh Halfpenny back after he missed the loss at England with a foot infection while George North impressed from the bench at Twickenham and Liam Williams and Hallam Amos returned from injury for Saracens and the Dragons respectively.