23-year-old Costelow replaces regional teammate Ioan Lloyd, who drops to the bench, in Warren Gatland’s starting XV who will be looking to bounce back from their heartbreaking late defeat against England at Twickenham last time out.
After recovering from a neck injury suffered in Wales opening day 27-26 defeat to Scotland in Cardiff, Costelow will be a welcome sight back in the Welsh side with Lloyd suffering a torrid afternoon in London a fortnight ago.
Cardiff number eight Mackenzie Martin is in line to make his debut for his country after being named amongst the replacements to play last year’s Grand Slam champions with Taine Basham dropping out.
Wales’ front row remains unchanged with Osprey Gareth Thomas at loosehead, Dragons Elliot Dee continues at hooker and the powerful Keiron Assiratti completes the three.
Captain Dafydd Jenkins continues his partnership at lock with Adam Beard. Alex Mann lines up at six, with in form Tommy Reffell on the other flank, whilst Aaron Wainwright starts at eight.
Tomas Williams is preferred once more to Gareth Davies at scrum-half, with Costelow partnering the Cardiff man at ten. Nick Tompkins lines up at inside centre with the experienced George North taking up the 13 jersey.
In the back three, Cam Winnett starts at full back, with Rio Dyer on one wing and Josh Adams on the other.
“We are excited to go out to Dublin and test ourselves against one of the leading sides in world rugby,” said head coach 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 XV to face Ireland:
Cam Winnett, Rio Dyer, George North, Nick Tompkins, Josh Adams, Sam Costelow, Tomos Williams, Gareth Thomas, Elliot Dee, Keiron Assiratti, Dafydd Jenkins (captain), Adam Beard, Alex Mann, Tommy Reffell, Aaron Wainwright.
Replacements:
Ryan Elias, Corey Domachowski, Dillon Lewis, Will Rowlands, Mazenzie Martin, Keiron Hardy, Ioan Lloyd, Mason Grady.
[Lead image: Welsh Rugby Union]
