Cardiff - Four players have been withdrawn from Wales' squad to face the Springboks in Washington DC on June 2.
The English-based trio of lock Luke Charteris (Bath), prop Tomas Francis (Exeter Chiefs) and wing Josh Adams (Worcester Warriors) are no longer available, while loose forward Josh Navidi is out injured.
The Test against the Boks falls outside World Rugby’s Test window and therefore Premiership Rugby Limited, which represents the English top-flight clubs, will not release the players.
As a result, coach Warren Gatland has dropped the trio for their entire summer tour, which also includes two Tests against Argentina.
Ashton Hewitt, Rhodri Jones and Aaron Wainwright have been called up as replacements.
Wing George North and loose forward Ross Moriarty, who are both returning from England to play for Welsh clubs, will tour with the squad.
The WRU confirmed that Navidi has been ruled out of the tour after dislocating a shoulder in Cardiff Blues’ Challenge Cup final victory last weekend.
"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,” Gatland told the Wales Rugby Union’s official website.
"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."
Regarding the absence of Navidi, Gatland added: "It is a blow for Josh 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 squad:
Forwards
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 (Gloucester - 20 Caps)
Aaron Wainwright (Dragons - *Uncapped)
Aaron Shingler (Scarlets - 17 Caps)'
Backs
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 - 6 Caps)
Owen Watkin (Ospreys - 4 Caps)
Scott Williams (Scarlets - 55 Caps)
Hallam Amos (Dragons - 15 Caps)
Steff Evans (Scarlets - 9 Caps)
Ashton Hewitt (Dragons - *Uncapped)
George North (Northampton Saints - 73 Caps)
Tom Prydie (Scarlets - 7 Caps)