Hooker Owens is not expected to recover in time from a back injury and will make a reserve list at best. He has been capped 91 times and led the side in this year’s Six Nations.

"We gave Ken as much time as possible but his back has not recovered," Gatland told reporters. "He might need an operation so he's not going to be available for the World Cup squad.

"He has not retired from rugby and he's hoping if he recovers and gets himself right on the pitch, potentially he may be available (as a reserve call-up) if we pick up injuries during the World Cup."

Back row Josh Macleod (26) and prop Will Davies-King (24) have also been released from the squad due to injury, with hooker Sam Parry (31) brought in to replace Owens.

Gatland has seen a number of his experienced players drop out of the squad in recent weeks. Back row Justin Tipuric (33), lock Alun Wyn Jones (37) and scrum half Rhys Webb (34) all announced their international retirements after being named in the preliminary selection.

Versatile forward Cory Hill (31), who can cover the second row and flanker positions, opted to take up a contract in Japan that makes him ineligible for the World Cup.

Wales have been drawn in Pool C in France along with Australia, Fiji, Georgia and Portugal. The top two teams in each group advance to the quarter-finals.