:Sam Costelow returns at flyhalf for Wales after injury for their clash against Ireland in Dublin on Saturday in the only change to the team from their last Six Nations outing.Costelow missed the 16-14 loss to England in their previous game two weeks ago with a neural neck injury but is back in the side that coach Warren Gatland named on Tuesday.Cardiff number eight Mackenzie Martin was named among the substitutes for the first time and is in line for his first cap if he comes on against the Irish.The 20-year-old from Cardiff replaces Taine Basham in the 23-man squad and could become Wales' 1,200th international.Costelow, 23, was forced off in the first half of Wales' opener against Scotland and his replacement Ioan Lloyd, who is also from Scarlets, helped orchestrate a fightback as they came from 27-0 behind to within one point of getting a result.But Lloyd drops back down to the bench after an ineffective performance against England at Twickenham.Wales are looking for their first success in this year's Six Nations but are up against a rampant Ireland, who have won both their opening fixtures."We are excited to go out to Dublin and test ourselves against one of the leading sides in world rugby.
It's a challenge we are relishing," Gatland said in a statement."We've made steps in the last couple of games and now it's about building on that, learning from those experiences and taking that into this weekend."It's about continuing to work hard, looking for accuracy in our performance across 80 minutes and also keeping our discipline," the coach added.Wales team: 15-Cameron Winnett, 14-Josh Adams, 13-George North, 12-Nick Tompkins, 11-Rio Dyer, 10-Sam Costelow, 9-Tomos Williams; 1-Gareth Thomas, 2-Elliot Dee, 3-Keiron