Cory Hill and Ellis Jenkins will co-captain an experimental Wales squad on their summer tour of the United States and Argentina.
Alun Wyn Jones, who has skippered his country since the 2017 Six Nations, has been given the summer off alongside fellow British & Irish Lions Taulupe Faletau, Leigh Halfpenny and Liam Williams.
George North and Ross Moriarty are the only members of the full Lions squad in New Zealand that have been picked to face South Africa in Washington D.C. before the two-Test series against the Pumas.
Cardiff Blues scrum-half Tomos Williams is the one uncapped player named by head coach Warren Gatland in the 31-man squad.
"This summer is a great opportunity for this squad to build on their experience, get Test match game time under their belt and face Rugby Championship opposition," Gatland said.
"We have picked a squad of 31 to try and give players as much game time as possible. It shows the depth we have built in recent years that we have just one uncapped player in the squad in Tomos, but he has been in a number of squads so knows the environment well.
"We have picked Cory and Ellis as co-captains, they are both leaders and have experience captaining at regional level so this is an opportunity for them to build on that.
"This summer is another step on our 2019 RWC [Rugby World Cup] path and a great opportunity to build on recent campaigns."
Wales are scheduled to play South Africa in Washington on June 2 before they head south and face Argentina June 9 and 16.