The summer tour starts with the historic clash against South Africa in Washington D.C., followed by the back-to-back contests with Argentina.
Hewitt and Wainwright join fellow Dragons Cory Hill, Hallam Amos, Elliot Dee and Ross Moriarty for the Wales trip which includes fixtures at the RFK Stadium in the US before Tests against the Pumas in San Juan and Santa Fe.
First called up into the 2017 Wales’ Six Nations squad, Hewitt missed the tournament due to a head injury, but has returned this campaign, scoring 7 tries in 21 appearances for the Men of Gwent.
Aaron Wainwright was selected as Dragons Young Player of the Year at the region’s end of season awards after a breakthrough season for the Academy product, playing 25 games.
Hewitt will compete with Steff Evans, George North and Tom Prydie for a berth on the wing, after Josh Adams was forced to pull out, whilst Wainwright’s inclusion comes after Josh Navidi’s withdrawal due to injury in the European Challenge Cup final in Bilbao.
Wales’ first summer tour test against South Africa on June 2, sits outside of the June test window (Test Window: Weekends of 9/10 June, 16/17 June and 23/24 June) and English based players will not be released by Premiership Rugby for the fixture.
As a result, Adams (Worcester Warriors), Tomas Francis (Exeter Chiefs) and former Dragon Luke Charteris (Bath) have been released from the squad as they were not available for the entire tour. Ross Moriarty and George North who are both returning to Wales will tour with the squad.
Following the fixture against South Africa, Wales face two tests against Argentina on June 9 and June 16 return to the U.K before the end of the test window. It was confirmed earlier that Channel 4 will broadcast all three fixtures live on free-to-air television, with highlights on S4C.
Wales head coach Warren Gatland said:
"We are really disappointed that Josh, Tomas and Luke have to miss out on the opportunity to tour with Wales and play international rugby this summer.
"It was a great opportunity for them to play for their country, press their claim in an important year and it is a shame supporters will not get to see them in the red of Wales.
"The situation is very clear for players playing in England going forward and heading into a RWC year.
"With the players unavailable to link up with the squad until the week of our second test match we have had to replace them in the squad."
"It is a blow for Josh (Navidi) to pick up the injury and miss out on the summer. He has been an important player for us over recent campaigns and has really impressed."
Wales v South Africa, RFK Stadium , Washington DC, Saturday 2 June, KO 17:00 (22:00 UK)
Argentina v Wales (1st Test), Estadio San Juan Del Dicentenario, San Juan, Saturday 9 June, KO 16:40 (20:40 UK)
Argentina v Wales (2nd Test),, Estadio Brigadier Lopez, Santa Fe Saturday 16 June, KO 16:40 (20:40 UK)
Rob Evans (Scarlets) (25 Caps)
Wyn Jones (Scarlets) (8 Caps)
Nicky Smith (Ospreys) (18 Caps)
Elliot Dee (Dragons) (7 Caps)
Ryan Elias (Scarlets) (2 Caps)
Rhodri Jones (Ospreys) (16 Caps)
Samson Lee (Scarlets) (38 Caps)
Dillon Lewis (Cardiff Blues) (2 Caps)
Adam Beard (Ospreys) (2 Caps)
Bradley Davies (Ospreys) (62 Caps)
Seb Davies (Cardiff Blues) (4 Caps)
Cory Hill (Dragons) (15 Caps) (Co-Captain)
James Davies (Scarlets) (1 Cap)
Ellis Jenkins (Cardiff Blues) (6 Caps) (Co-Captain)
Ross Moriarty (Dragons) (20 Caps)
Aaron Wainwright (Dragons) (*Uncapped)
Aaron Shingler (Scarlets) (17 Caps)`
Aled Davies (Scarlets) (8 Caps)
Gareth Davies (Scarlets) (32 Caps)
Tomos Williams (Cardiff Blues) (*Uncapped)
Gareth Anscombe (Cardiff Blues) (15 Caps)
Rhys Patchell (Scarlets) (8 Caps)
Hadleigh Parkes (Scarlets) (55 Caps)
Owen Watkin (Ospreys) (4 Caps)
Scott Williams (Scarlets) (6 Caps)
Hallam Amos (Dragons) (15 Caps)
Steff Evans (Scarlets) (9 Caps)
Ashton Hewitt (Dragons) (*Uncapped)
George North (Ospreys) (73 Caps)
Tom Prydie (Scarlets) (7 Caps)
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