Northampton Saints are in "open discussions" with George North's representatives to end his Saints contract early ahead of Wales' summer tour.
The Welsh Rugby Union said on Wednesday that North and Gloucester back-row forward Ross Moriarty, who are both returning to Wales to join the Ospreys and Dragons respectively this summer, will tour.
They are among a 30-man group for Tests against South Africa in Washington DC on June 2 and Argentina in South America on June 9 and 16.
But Worcester wing Josh Adams, Exeter prop Tomas Francis and Bath lock Luke Charteris will not be part of the squad.
The Springboks clash falls outside World Rugby's June Test window, and England-based players have not been made available by Premiership Rugby for that fixture.
The WRU said that Adams, Francis and Charteris have been released from the squad as they are unavailable for the whole tour.
The official Test window next month is from June 9-23.
Wales head coach Warren Gatland, meanwhile, has expressed his disappointment after releasing three England-based players from his squad.
Dragons wing Ashton Hewitt and his fellow uncapped team-mate, back-row forward Aaron Wainwright, have been called into the squad, along with Ospreys prop Rhodri Jones.
Gatland had already decided to rest the vast majority of Wales players who toured New Zealand with the British and Irish Lions last summer, meaning players like Alun-Wyn Jones, Leigh Halfpenny, Liam Williams, Dan Biggar, Ken Owens and Justin Tipuric will not be involved.