Blues winger Richard Mustoe, along with Scarlets flanker Rob McCusker, will become standby players for Wales's tour of USA and Canada.
Wales coach Robin McBryde has made the final cut to reveal his 26-man touring squad set to leave for Canada and America this Saturday.
Blues wing Richard Mustoe and Scarlets back row Rob McCusker join Dragons quartet Luke Charteris, Jason Tovey, Lewis Evans and Dan Lydiate and remain at home as standby players who could still be called out for the two-Test trip to Toronto and Chicago.
"We've trimmed the squad right down now to ensure that everyone has involvement on the tour and to continue the philosophy of having a tight knit group who are all working for each other to one aim," said McBryde.
"That attitude to squad selection has served us well in the recent past and helps to create the right atmosphere of intensity and competition and competition for places in the camp.
"Those players that have been training with us this week but are left behind will hopefully have learned from the experience and have been given a taste of what international rugby is all about.
"I'm sure all of them will be hungry for more and will be ready and waiting if we need to call on them over the course of the next few weeks.
"We have all the right contingency planning in place now to provide us with adequate cover should we lose players through injury or should they be called elsewhere."
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.