Matthew Rees believes that Wales' success on world and European stages has contributed to players being in demand from wealthy French clubs.
Centre Jamie Roberts is set to join Mike Phillips, James Hook, Gethin Jenkins and Luke Charteris in France next season after rejecting a new deal from Cardiff Blues. Press Association Sport understands that 44 times-capped Roberts will join wealthy Parisians Racing Metro, although no announcement has yet been made about his destination.
"I am not sure the English, Welsh and Irish sides will be able to compete with the French teams," former Wales captain Matthew Rees said, ahead of packing down against Argentina on Saturday. "So it comes down to a question for the individual concerned. Jamie has made the decision to go to France."
Rees went on: "One of the biggest things is the respect Welsh players have now which we probably didn't have in the past. French clubs are interested in coming in and poaching players. It's up to the (Welsh) regions and the Welsh Rugby Union to sort it out."
Roberts, meanwhile, says he is "absolutely certain" the time has come for him to sample a new rugby environment. He has, though, already been reminded of the need to secure release for key Wales training camps when he starts a lucrative club career across the English Channel.
The current France-based quartet missed Wales' critical pre-autumn training stint in Poland last week due to club commitments.
While Toulon prop Jenkins still starts against Argentina on Saturday, Phillips and Hook are on the bench and Charteris plays for Perpignan this weekend after a deal was struck between his club and Welsh Rugby Union that would see him freed in return to face Australia on December 1.
Roberts said: "I am proud of what I have achieved so far in my rugby playing career and remain determined to continue to aspire to win international honours for Wales. This has been an extremely difficult decision, but I am absolutely certain it is the correct time for me to enter a new stage of my career."
Faced with seeing another star name leave Wales, national squad skills coach Neil Jenkins said: "It is obviously a difficult scenario for us. We want our best players playing in Wales as often as possible.
"The most important thing from our point of view is that whenever Jamie does go, he gets full release and he can come to these pre-autumn and pre-Six Nations training camps. If that is the case, Jamie will be a full part of this Wales squad going forward."