San Francisco Frontiers - Costelow returns for Wales Six Nations clash against Ireland

The Scarlets number 10 went off because of a neck problem he suffered when Wales were beaten 27-26 by opening tournament opponents Scotland.

He was replaced by Ioan Lloyd, who started at fly-half in the Twickenham defeat against England, but Costelow now returns as a solitary change from that game.

There are further starts for squad newcomers Cameron Winnett and Alex Mann, while centre George North wins his 120th cap and is only the third Wales player to reach that mark after Alun Wyn Jones and Gethin Jenkins.

"We are excited to go out to Dublin and test ourselves against one of the leading sides in world rugby," said Wales coach Warren Gatland. "It's a challenge we are relishing.

"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."

Wales are second from bottom of the Six Nations table after their two defeats while Ireland are on course for an unprecedented second straight Six Nations Grand Slam after wins against France and Italy.

Wales team to face Ireland in the Six Nations at Dublin's Aviva Stadium on Saturday (1415 GMT):

(15-1)

Cameron Winnett; Josh Adams, George North, Nick Tompkins, Rio Dyer; Sam Costelow, Tomos Williams; Aaron Wainwright, Tommy Reffell, Alex Mann; Adam Beard, Dafydd Jenkins (capt); Keiron Assiratti, Elliot Dee, Gareth Thomas

Replacements: Ryan Elias, Corey Domachowski, Dillon Lewis, Will Rowlands, Mackenzie Martin, Kieran Hardy, Ioan Lloyd, Mason Grady

Coach: Warren Gatland (NZL)

W.Thompson--SFF