SOME of the NRL's biggest stars have called for Sonny Bill Williams's shock exit to French rugby union to spark massive changes to the salary cap before more players are lost to the game.

As Australian legal representatives were last night trying to locate Williams in Europe to deliver a subpoena on him to appear on Tuesday in the NSW Supreme Court, other players warned the NRL the likes of Greg Inglis, Israel Folau, Krisnan Inu and Jarryd Hayne could be the next to go unless the salary cap is modified.

Among those to speak out after the revelation in yesterday's Herald that Williams's legal team was preparing to challenge the salary cap if the NRL was successful in preventing him from switching codes were Inu, Setaimata Sa, Steven Price, Craig Fitzgibbon, Luke O'Donnell, Chris Walker and Robbie Farah. While few agreed with the manner of his sudden exit from the Bulldogs before the end of the season, most supported his right to take up the $3 million, two-year deal with Toulon and predicted others would do the same.

"He has just started the trend, I know heaps of guys that are thinking of switching already," said Inu, who last year considered walking out on a lucrative contract with Parramatta to complete a religious mission.

"Expect more players to be leaving - that is the only thing going to be happening. I read on the weekend that of all the four football codes we are the least paid and the most well-known after soccer, so something definitely needs to change.

"The players want more money, and rugby is a massive threat. It is a good game, not too different to league."

Asked if there was a chance he would switch to rugby, Inu said: "I'm contracted for another two years. Hopefully by the time I need to sign my next contract they would have fixed the salary cap so I don't need to worry about it."

Sa, the 20-year-old Roosters utility who, like Williams, has expressed a desire to play for the All Blacks, reiterated that players would leave in droves if the cap remained the same.

"All the rugby league players are wondering where all the money is going," Sa said. "It's not just going to be him [Williams] going, it will be the next superstar after him.

"The kids coming through are going to see how much drama there is trying to get money in the NRL and they'll go to rugby."

Aside from the amount of the $4.1 million salary cap, the players' main issues are that it discourages loyalty and the restrictions on third-party payments are too severe. Walker said the salary cap was a restraint of trade.

"I stand up and applaud Sonny Bill," he said. "We go out and bust our arses and we can't even earn what people are willing to pay us. At the end of our careers, 99 per cent of us can't walk properly and we should be on more money than the AFL or union guys because our game is a lot harder and more loved but we're on a pittance compared to what those guys get. Surely our television contract is worth more than rugby union so how can that be?"

After admitting he secured his latest one-year contract extension for next season only after the Roosters lost Anthony Tupou to Cronulla and David Shillington to Canberra, Fitzgibbon claimed the salary cap, as it stands, "punishes loyalty".

"It's basically impossible to be loyal," the veteran back-rower said. "If a couple of young kids signed with the Roosters, I'm stuffed. But there's a bigger issue at hand here - Mark Gasnier, Craig Gower, not to mention the English Super League. There's obviously an issue there with the salary cap - people don't want to stay here.

"It might be a little too late already. Sooner or later, who's going to take a step forward? There's only one of him [Williams], and I don't know if we're going to see another one."

Warriors captain Price, who was the spokesman for the players during the Dogs' 2002 salary cap saga, said the game needed a ceiling on player payments but argued individuals should not be prevented from signing personal sponsorship deals. "Allowing corporations to pay players would certainly help," he said. "We play a hard game and at the end of it you're going to have a lot of things wrong with you physically and throughout the whole thing you're told you can only earn this much money."

O'Donnell understood the role of the cap in maintaining an even competition but he added: "It is hard to take. You'd like to think you get what you're worth."

Asked whether he would walk out on a contract, Farah said: "You'd like to think that you wouldn't but at the end of the day is someone offered you a contract like that I don't know."