Toulon owner Mourad Boudjellal has suggested Leigh Halfpenny will not be paid by the club if he tours New Zealand with Wales in June.
The full-back has not played for his French club in the 2015-16 season after suffering a serious knee injury in Wales’ final World Cup warm-up against Italy in September 2015.
“I’m not paying anyone who’s not here in June,” Boudjellal said.
“If anyone leaves in June, wherever they go, they’ll have to pay them.”
The French Top 14 final will be played on 24 June, the eve of Wales’ third and final Test against the All Blacks in Dunedin.
France are expected to tour Argentina without players involved in the French play-off system, which continues during the international window.
World Rugby’s article nine states that clubs have to release players during official international periods, with several of Toulon’s South Africans also possible absentees.
“We’ll go to all the tribunals in the world, but anyone who’s not playing for us won’t be paid by the club,” Boudjellal added.
“I’m not stopping anyone leaving because there is article nine – but anyone who leaves us before our final match won’t be paid by the club.”
Halfpenny had been scheduled to return in mid-April and was registered in Toulon’s European Champions Cup squad.
The 27-year-old may be fit by the time of the Wales tour and the French play-offs.
“After the episode of the World Cup and the episode of the injuries, the third episode that is about to happen is the [fixture] calendar,” warned Boudjellal.
“We could find ourselves in June without three or four players at least because they are going to play friendly matches for their federations.
“I hope the federations have the intelligence to see that in a World Cup year, they’ll say to themselves that the Top 14 is a real competition and you have to respect the clubs who look after the players all year.”
Boudjellal’s comments come as Warren Gatland prepares to name the Wales squad on Tuesday 10 December for the Test against England at Twickenham on 29 May.
Toulon lie third in the French Top 14 with three rounds of the regular season still to play.