His new two-year contract will see him become the highest paid player across both league and union - $5 million a season - so it's no surprise that Williams isn't taking his stint in England's second tier lightly.
According to Nine News, the 34-year-old is residing in Kingsliff, attending a "torturous training camp" at the Surfing Australia high performance centre.
However, unlike the start of his career, Williams is now focused on longevity instead of bulking up. The training regime designed for the former All Black has a strong emphasis on injury prevention, says high performance coach Michael Crisp.
“He’s amazing.” Crisp said. “He’s 34. 110 kilos. He’s like three humans.”
The man behind his strength and condition program is former Roosters S&C whiz Keegan Smith.
“The kind of training that we’re doing, I don’t think any player’s ever actually done to prepare themselves for footy,” Smith explained.
“That opens up the possibility of getting some results that haven’t been seen as well. So we’re excited.”
You can see footage of Williams' getting his body in shape below.