Sonny Bill Williams turned down twice as much money to remain a Bulldog last season, but the Kiwi superstar says the Willie Mason saga has taught him not to put loyalty ahead of family any more.

In a statement which is sure to spark the interest of NRL clubs around the country, Williams says he no longer believes in loyalty and that his next contract negotiation will be decided by what is best for himself and his family.

However, after being persuaded by Mason to show loyalty to the Bulldogs last season, that time won't come for another four years as the 22-year-old is contracted until the end of 2012.

Williams says clubs use loyalty to try and convince marquee players to stay but then cry salary cap restrictions when senior players are trying to negotiate extended deals and instead sign younger players.

"I think players this day and age have to look after themselves and their families first and foremost," Williams told the Nine Network.

"A lot of people may say I'm a hypocrite for saying that after the thing with Mason, but the thing with Mason is totally different. The thing with Mason and the reason I was upset was he said one thing and did the total opposite."

Mason walked out on the Bulldogs last November to join the Sydney Roosters and Williams remains upset that his former teammate convinced him to remain at Belmore for loyalty but turned his back on his mates less than 12 months later because of a feud with then club chief executive Malcolm Noad.

Williams claimed Mason was using his feelings for Noad to hide the real reason he left the club.

"I know Willie and all the boys know Willie, he is big on diversions and I think that was one of them for tomorrow night's game," he said.

Williams and Mason will clash for the first time when the Dogs host the Roosters at ANZ Stadium.

While they play on opposite sides of the field, they are salivating at the prospect of lining each other up in Friday's blockbuster.

"Of course there is going to be nerves but in saying that if I see him on the field I'm not going to take a backward step," said Williams.

"It's going to be a big match with a bit of a twist."

While Mason downplayed any feud with Williams, the Bulldog superstar avoided a direct answer when asked if he was still friends with Mason.

"You know all week people have been asking that question and my main focus this week is 7.30 tomorrow night. It's the game. Whatever happens after that happens," he said.

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