Wales defence coach Shaun Edwards has revealed that Craig Mitchell will miss the nation's first Test against Japan on Saturday with an ankle injury.
The 27-year-old, who has made 14 appearances for his country, is, however, expected to be fit for the second Test on June 15.
"It's an old injury that's flared up again. Hopefully he will be right for the second Test," Edwards told BBC Sport.
"I think it's more of an injury that he carried over here because he hasn't trained since he's been here."
Bradley Davies, meanwhile, is expected to captain the side.
