Most played their part in the 2014 Under-20 Six Nations and ten players were part of Wales' squad that reached the final of the JWC last season.
Two players, Hallam Amos and Dafydd Howells, have already been capped at senior level and Hayward, whose side will play Scotland in a warm-up game on Wednesday May 14 at the Brewery Field, said his young troops are wise beyond their years.
"We're happy with the strength in depth we built during the Six Nations through ensuring everyone got a decent amount of game time in order to develop at this level and stake a claim for a place in this squad," he said.
"Having reviewed our Six Nations performances, we can be happy with our performance against Ireland, where our set-piece was key in grinding out an important win in Athlone, we lost to France, the other Six Nations team in our JWC pool, by one score and we were down to 14 men for 20 minutes in that game.
"We learned a lot of lessons in that match and if we get the tactical game right and the players adapt to the opposition in front of them, we certainly have a chance against all the teams in our group."