The Welsh youngsters got their Under 20 Six Nations off to a good start with a 26-9 win over Italy at Eirias last weekend - but Hayward insists his side will have to step up a gear to beat the Irish.
In the backline, Ashton Hewitt and Garyn Smith come in for Dafydd Howells and Harri Evans - with captain Steffan Hughes switching from inside to outside centre. Up front, Nicky Smith and Ethan Lewis come into the front row for Callum Lewis and Elliot Dee, Scott Andrews comes into the second row while Ben Roach returns to his usual back row positon, taking up the No 8 berth with James Benjamin moving to the openside flank.
Hayward said: "We will need to step up a gear defensively against Ireland as they will pose a different challenge to Italy, plus they scored 30 points against Scotland. I'm confident we can rise to that challenge as we've worked hard on that area of our game under Richard Hodges.
"Along with a solid defence, our discipline needs to be good and we need to attack in the right areas and at the right times.
"I've told the players that Friday will be a totally different challenge playing away from home - the environment and the crowd will be something new for most of the players - but a challenge that will stand us in good stead as we prepare for the Junior World Championship in New Zealand."
Wales Under 20 team v Ireland (Friday 7 February, 7.35pm, Dubarry Park, Athlone):
Afon Bagshaw (RGC); Ashton Hewitt (Dragons), Steffan Hughes (capt, Scarlets), Garyn Smith (Blues), Joshua Adams (Scarlets); Ethan Davies (Dragons), Tom Williams (Blues); Nicky Smith (Ospreys),Ethan Lewis (Blues), Nicky Thomas (Ospreys), Scott Andrews (Dragons), James Sheekey (Blues), Will Boyde (Carmarthen), James Benjamin (Dragons) Ben Roach (Blues)
Scott Otten (Ospreys), Luke Garrett (Dragons), Callum Lewis (Blues), Rory Thornton (Ospreys) Ollie Griffiths (Dragons), Connor Lloyd (Scarlets), Luke Price (Ospreys), Tyler Morgan (Dragons)