Wales head coach Warren Gatland has recalled fly-half Sam Costelow in one starting change for the Six Nations trip to face Ireland in Dublin on Saturday.

Uncapped Cardiff number eight Mackenzie Martin is in as a replacement with Taine Basham out of the 23-man squad.

Wales have lost two Six Nations games while unbeaten Ireland remain on course for a second successive Grand Slam.

Wales' defeats against Scotland and England have been by a combined margin of just three points, while Andy Farrell's side have comfortably beaten France and Italy to top the table on 10 points, seven more than their opponents in round three.

Fly-half change

Costelow, 23, started the opening game against Scotland, but was forced off with a neck injury in the first half.

He was replaced by Lloyd, who helped orchestrate Wales' thrilling fightback from 27-0 adrift before the eventual one-point defeat in Cardiff.

With Costelow sidelined, Lloyd's first Wales start came in the fly-half role for the 16-14 defeat at Twickenham.

Martin, 20, is in line to become the third Cardiff player to make his Wales debut in this campaign following full-back Cameron Winnett and flanker Alex Mann.

This will be only his 10th professional game in his first senior season with five starts and four replacement appearances so far for Cardiff.

If Martin comes on, he will become the 1,200th Wales men's senior international.

Harlequins prop Dillon Lewis is also included on the bench following injuries to tight-heads Leon Brown and Archie Griffin.

"We are excited to go out to Dublin and test ourselves against one of the leading sides in world rugby," said 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: Winnett; Adams, North, Tompkins, Dyer; Costelow, Tomos Williams; G Thomas, Dee, Assiratti, Jenkins (capt), Beard, Mann, Reffell, Wainwright.

Replacements: Elias, Domachoswki, D Lewis, Rowlands, M Martin, Hardy, I Lloyd, Grady.