In his return to rugby league after a four-year absence, Williams was a key figure in the Roosters' premiership win last season and was rewarded with selection in the world team of the year.
This season could be his last in rugby league and, with his reintegration into the game complete, no pre-season boxing bout and no injury concerns - a shoulder injury interrupted his 2013 preparation - the Roosters are quietly confident Williams will become an even better player this year as they defend their NRL crown.
"Sonny will be hoping for that; we will be hoping for that," Robinson told AAP.
"You don't underestimate Sonny no matter what circumstances lead him into a competition or a code. He has enough grit and determination to make anything work.
"We are really focused on getting better as a team and I'm sure he is as an individual.
"We are not done - we want to keep improving.
"Sonny can build on what he did last year."
This time last year, opinion was divided on how Williams would fare after defecting to rugby union but the Kiwi dual international more than answered his critics with some memorable performances.
Williams has committed to New Zealand rugby for two years at the end of this season, which means the constant speculation that swirled around his future last year won't be a distraction for the Roosters in 2014.
"He has been really clear and honest about what he is doing this year and what he wants to do next year so that speculation won't be there this year," Robinson said.
"Whatever he decides to do, he will do. Whatever challenges him, he will decide to do.
"It's perfectly honest - he doesn't short-cut any team he signs on for. He gives it 100 per cent.
"People have different views about the way of signing those one-year contracts but he challenges himself and he challenges the team he goes to, so I think it is an admirable thing that he does.
"Sonny will create enough headlines this year, but that is what we want in our code. We are grateful to have him here at the Roosters for another year and I think the code should be as well."
