Sydney Roosters coach Trent Robinson has ruled out a return to the NRL for Sonny Bill Williams against Wests Tigers next week despite the premiers' mounting injury toll.

The 35-year-old Williams and his family were released from quarantine on Thursday afternoon, hours before the Roosters' casualty ward grew during their 24-6 loss to Melbourne at the SCG.

Luke Keary, Mitch Aubusson and Lachlan Lam are all expected to be sidelined for several weeks, joining seven of Robinson's regular starting 17 in the casualty ward.

But rather than rush Williams in, Robinson confirmed he is aiming to play the dual-code superstar in round 17 against Canberra.

"I'm basing it on the training that we had to do when we came back (from the COVID-19 break), you need about three weeks out of isolation and all of that to get going," Robinson said.

"That would be it. No one get excited about next week."

However, given the injury concerns at the Roosters, Williams' timing could not be more perfect to boost morale.

After completing a medical examination, the New Zealand superstar is expected to have his first training session with his Roosters teammates at the weekend.

Williams was using gym equipment while in quarantine and, although he's had minor knee surgery, is expected to hit the ground running after his recent stint with Toronto in the Super League.

"We're doing good. We're very happy," Williams told the waiting media before heading off for a biosecurity check with his wife and four children.

"I'll start training when we get the test back."

Williams last played in the NRL in 2014, in between stretches in rugby union where he earned 58 caps for the All Blacks and won a World Cup.

Despite his achievements, Robinson sensed Williams would rise to the challenge of playing in the NRL again and play a role in the Roosters' charge to a third successive title.

"We can talk about all his attributes and people can see them, it's the courage he has to play footy ... that's the biggest one," Robinson said.

"Around all the talents you see, the man has got a fire in him, he's got a hunger to perform and he loves playing in a team environment."

Robinson has played his cards close to his chest when asked about how he planned to use the veteran.

"I'd like to keep those private, the conversations between Sonny and I about the way we'll use him," he said.

"We've had lots of discussions and then we'll start to see him move and how he connects with the guys around him and that will give us a further idea about how we will use him."