Uncapped pair Freddie Thomas and Blair Murray have been included in Wales’ 35-man squad.
Gatland has also re-called experience in Gareth Anscombe, Will Rowlands, Nicky Smith and Tomos Williams, as well as handing a shock recall to 31-year-old Dragons scrum-half Rhodri Williams, more than 10 years after his last Wales cap.
Dewi Lake retains the captaincy despite the return of Jac Morgan, who missed the summer tour.
Ben Carter has withdrawn through injury while Wales are also without Six Nations captain Dafydd Jenkins and British and Irish Lions trio Taulupe Faletau, Josh Adams and Liam Williams as well as recently retired Gareth Davies.
Forwards: Nicky Smith, Gareth Thomas, Kemsley Mathias, Ryan Elias, Dewi Lake, Evan Lloyd, Henry Thomas, Keiron Assiratti, Archie Griffin, Freddie Thomas, Christ Tshiunza, Teddy Williams, Will Rowlands, Adam Beard, Taine Plumtree, James Botham, Jac Morgan, Tommy Reffell, Aaron Wainwright.
Backs: Tomos Williams, Rhodri Williams, Ellis Bevan, Sam Costelow, Gareth Anscombe, Ben Thomas, Nick Tompkins, Max Llewellyn, Eddie James, Owen Watkin, Mason Grady, Blair Murray, Rio Dyer, Josh Hathaway, Tom Rogers, Cameron Winnett.