All Black centre Williams won a World Cup winners' medal in 2011 after making his name in the 13-man code with the Canterbury Bulldogs.
And while Folau still has a long way to go to match Williams' achievements in union, Wallaby centre Anthony Faingaa sees plenty of similarities between the two and insists the pressure to live up to his reputation won't have a negative effect on the 23-year-old.
"Some of the traits you see in Sonny Bill you see in Izzy Folau," said Faingaa, who is set to play against Australia's bright, new hope when the Reds host the Waratahs in Brisbane on Saturday.
"He does all the basics well, obviously transferring some of his stuff from rugby league into rugby union.
"He runs the ball really hard, he offloads really well.
"He's had a lot of pressure, going to AFL, being one of the top players in rugby league.
"So I don't think this is going to hassle him too much. He's a rugby player now. There's always pressure when you play, especially for him."
Folau has already impressed in his early outings for the Tahs, crossing for a brace of tries on his debut in the friendly win over the Rebels and the starring again as Michael Cheika's men were narrowly beaten by the Crusaders in their final pre-season outing.
Cheika is expected to start at full back or on the wing when the Sydney-based side travel to Queensland this weekend but Reds boss Ewen McKenzie is tipping the Waratah's new weapon to pop up all over the park.
"He (Cheika) won't bog him down with too much detail," said McKenzie, who feels the Tahs will treat Folau the same as he and his coaches treat Wallaby wing Digby Ioane.
'He'll just back him to play and I think for a player in his situation that will be the best thing.
"We just let Digby play. We've got some plays and moves, but Digby roams and that's why he touches the ball more than anyone else just about every game."