Sky Sports' Ieuan Evans says that Taulupe Faletau's move to Bath is 'rather worrying' for Welsh rugby.
Bath announced on Wednesday that Wales No 8 Faletau will join the club at the end of the current season, ending months of speculation that the loose forward would leave the Dragons in favour of a move to the Premiership.
Former Wales international Evans says the signing of Faletau is a great scoop from Bath, but a worrying outcome for the WRU.
"It's an interesting one for Wales rugby because 'Gatland's Law' comes into play," Evans said on the Sky Sports European Rugby podcast.
"Not that it's written in law as 'Gatland's Law', but there's an agreement between the union and the regional entities that he's only allowed so many wildcards, or players that are playing outside the Welsh regions.
"Obviously with a number of players now gathering pace who are a significant part of Gatland's Wales squad - like George North, like Jamie Roberts, like Luke Charteris, Rhys Priestland and now Taulupe Faletau - it makes his two wildcards selection rather difficult.
"It's great news for Bath. They have an outstanding No 8 joining them, a potential Lion in a couple of years' time, and a regular player for Wales. He really is an outstanding young player.
"So they're delighted, no doubt, but from Wales' perspective, it's rather worrying I would suggest."
Evans believes it will be tough to know exactly what effect this will have on Gatland and Wales until more detail around Faletau's availability to play for his country become available.
"We are speculating on the contents of his release policy within his contract with Bath," said the retired winger. "What sort of release is he allow? Is he allowed full release or not?
"George North was able, within his Saints agreement I believe, to have full release. Whether that's the case with Taulupe Faletau remains to be seen.
"Whether or not it will mean other players are going to go across the bridge to peddle their wares, remains to be seen.
"There are so many caveats within 'Gatland's Law' as to what's allowed and what's not allowed. Are there opportunities beyond those two so-called wildcards to expand to other players who are playing outside Wales?
"There are so many things that aren't quite written in stone, they are slightly ambiguous for obvious reasons.
"It remains to be seen how it affects Warren Gatland's ability to pick his strongest XV come the Six Nations and further international tournaments next season."