Scarlets captain Ken Owens has insisted no more could have been done to keep Liam Williams in Welsh rugby.
Wales full-back Williams will line up for the Scarlets against his future employers Saracens on Sunday.
The European Champions Cup tie could be one of his final cross-border matches in a Scarlets shirt before the 25-year-old joins Taulupe Faletau, Jamie Roberts, George North, Rhys Priestland and other Welshmen in the Aviva Premiership.
Scarlets coach Wayne Pivac has claimed the deal offered to Williams to stay was not short of the one dangled by Sarries and that the move was made for personal reasons.
But Owens has suggested it was more the lure of playing for the European champions.
“He’s going to be a big loss, but he has to do what he feels is best for him and his career,” said Owens.
“I just wish him all the best. Going to the best side in Europe is not a bad way to improve yourself.
“My understanding is that the region and the WRU did their best to keep him, but Liam has done what he thinks is best for him.
“But that’s the professional game and what we are up against these days.”
Williams has made his name in Wales as a full-back who can also operate on the wing, but he is likely to be regularly out wide for Saracens as a replacement for Chris Ashton.
Former England wing Ashton is leaving for Toulon at the end of the season and Sarries view Williams as the player to fill that gap rather than dislodge their England full-back Andy Goode.
Owens added: “Liam’s loss is huge. He’s a world class player and as a full-back I think he’s been one of the best players in the world over the past year.
“He’s done on the very highest stage. In New Zealand on tour last summer against the All Blacks, he was magnificent.
“He will give Saracens a good attacking game and a good kicking game, too. He’s a great bloke, too, and he’ll bring true character to that side.
“Saracens already have a magnificent squad, but Liam will add to it. With Alex Goode there at the back, Liam will provide a different threat.”
In the short-term, Owens is hopeful Williams can play his part in what would be a memorable Scarlets victory this Sunday.
Should the Scarlets follow up their victory over Toulon with another major scalp it would keep alive their hopes of progressing to the knockout stages.
“We have to take confidence from our recent run of matches. We went pretty well against Toulon in Europe, both home and away, although we were disappointed with the result in France.
“We need a big win on Sunday, but why not? We have done special things in Europe in the past and we have already beaten Toulon this season.
“If we can get a good win, then we can go into the last round still capable of doing something.”
