The 27-year-old All Black centre switched codes in controversial circumstances just over four years ago, walking out on his contract with Canterbury Bulldogs to sign for wealthy French club Toulon, but is poised to make his return to league in 2013 with the Roosters.
"We've got to sign the contract first, that's the next step," said Robinson, who insisted he would have no problems coping with the "aura" surrounding the superstar.
The 2011 World Cup winner left Waikato Chiefs earlier this year to play his rugby in Japan and has also embarked on a part-time boxing career but has a handshake agreement to join the Roosters next season.
Robinson, who has returned to the Sydney club from a two-year stint in Super League with Catalan Dragons, told his first press conference that he had already spoken to Williams about his proposed move to Bondi Junction.
"If Sonny does come over, anyone who has dealt with him knows he's a great professional and a great leader with the way he lives his life," Robinson added.
"As far as his personality goes, I'm not worried about the aura around him. All the research I've done suggests he's a good person.
"I've had a chat to Sonny because I want to be ready to integrate him into the group and I think he's positive about what might happen as well.
"If he comes back to the NRL, it will be huge positive for our sport. I'm definitely happy for him to come back in when he's finished his business in Japan."
- Sports & Recreation
- Canterbury Bulldogs