Cooper, who started Wales’ opening RBS 6 Nations fixtures against England and Scotland, is definitely out of the remainder of the Cardiff Blues’ season including their Amlin Challenge Cup quarter-final with Newcastle this weekend.

The surgery will keep him out for at least two months and Blues boss Dai Young is certain Cooper will not add to his 46 caps this summer.

He said: “Gareth is going to have a hernia operation. He will be out for six to eight weeks, so obviously he is doubtful for the New Zealand tour.”

Cooper’s injury adds to Warren Gatland’s woes with Tom Shanklin, Robin Sowden Taylor, Gary Powell and Sam Hobbs already unavailable.

Wales face South Africa on June 5 in Cardiff before their daunting trip to play the All Blacks in a two-Test encounter.