Uncapped forwards Dewi Lake and Taine Basham have been called into Wales' Guinness Six Nations squad ahead of Saturday's showdown with Ireland.
The Wales U-20 internationals have been training with the senior squad in recent weeks, the Welsh Rugby Union (WU) said.
And Ospreys hooker Lake and Dragons back-row forward Basham have now been formally added to head coach Wayne Pivac's group.
It is Lake's first senior call-up, but fellow 20-year-old Basham was a squad member for a non-cap fixture against the Barbarians in November.
Pivac originally selected 38 players for the Six Nations, which Wales began with a 42-0 victory over Italy last weekend.
Cardiff Blues wing Owen Lane, though, was released last month after suffering a hamstring injury.
Lane's Blues colleague Josh Navidi, who remains part of the squad, is sidelined because of hamstring trouble, while Saracens back Liam Williams has not yet recovered from an ankle injury that ended his World Cup in semi-final week.
But Dragons hooker Elliot Dee, Ospreys centre Owen Watkin and Scarlets scrum-half Gareth Davies are expected to be in the selection mix for Saturday's appointment in Dublin after resuming full training following injuries.
Elsewhere, Anthony Watson will miss a second successive Six Nations match after suffering a setback in his recovery from a calf problem.
The England wing has been ruled out of Saturday's Calcutta Cup showdown with Scotland, pointing to the retention of George Furbank at full-back.
Watson suffered the injury on Champions Cup duty for Bath last month and while he was pencilled in to start the 24-17 defeat by France that opened the Championship, he was forced to withdraw on the eve of the team announcement in Paris.