Rhys Webb will become ineligible to play for Wales after the country's rugby union overhauled its selection policy.
Under the changes, those playing their domestic rugby outside Wales will now be available for the national team providing they have won 60 caps or more.
The old system, which was widely known as 'Gatland's Law' and capped the number of selections from outside the country, had come under increasing pressure over recent months, with the likes of Webb, Dan Biggar and Liam Williams all securing deals to play outside Wales.
The number of 'wildcard' selections had been set to drop from four to two by the 2019-20 season, which would likely have left Wales without a number of their top stars.
Wales' new Senior Player Selection Policy, which is similar to that used in Australia, will not immediately impact those currently under contract at non-Welsh clubs, meaning players like Williams, who joined Saracens on a three-year deal from the start of the current season, has plenty of time to add to his existing tally of 43 caps.
Biggar will leave the Ospreys to join Northampton Saints for the 2018-19 campaign but sits on 56 Wales caps and, fitness permitting, should hit the magic number before having to worry about his own international future.
British and Irish Lions scrum-half Webb is set to be the biggest loser as a result of the changes, having made just 28 appearances for his country and agreed to join Toulon from next season.
WRU chief executive Martyn Phillips said: "We have decided to make these changes to protect the 'investment' made by Welsh rugby - by our coaches, supporters, clubs, communities and fellow team members - in those individuals who rise to the top and make it to international rugby.
"We have established a clear incentive for those players approaching the prime of their rugby playing careers to stay in Wales and it is now there in black and white for everyone to see.
"The revamped policy will be reviewed periodically but, fundamentally, if you have less than 60 caps and you leave Wales then you won't be selected by your country again until you return."
Gatland, meanwhile, would prefer a free selection.
"For me as a national coach, if I was being perfectly selfish, would I have a policy? No I wouldn't," he told WRU TV.
"But it's not about what's best for me and the national team, it's about what's best for Welsh rugby.
"The best thing for Welsh rugby and for the Union to support the regions is how do we try and keep a number of the best players in Wales for as long as we possibly can?
"But we know we're under pressure from market forces."
Northampton wing George North (69 caps), Bath number eight Taulupe Faletau (66) and Harlequins centre Jamie Roberts (93) all stand to benefit from the change.