Cooper Cronk hasn't ruled out playing on into 2020 and a shot at crossing the illustrious 400-game NRL milestone.

Having blown out the candles on his 35th birthday cake on Wednesday, the Sydney Roosters premiership hero was widely expected to hang up his boots at the end of his current contract next season.

However the former Queensland and Australian playmaker kept the rugby league world guessing on Friday when he casually said he hadn't decided either way on a 17th campaign.

Leaving the door ajar means he could potentially bring up 400 games before retiring.

He will become just the fourth player in the league's history to crack 350 games when he runs out for the first time next year.

Former Melbourne teammate Cameron Smith (384 games) is expected to be the first to bring up 400 midway through next year, provided the off-contract veteran can strike a new deal with the Storm.

Fronting a press conference at the SCG to announce Ikon Services as the club's new sleeve sponsor, Cronk caught many off guard when he said he may play on for two years and past his 36th birthday.

"I haven't even got back to training and you're asking me if next year is my last," Cronk said.

"I haven't had that conversation but I'm not really sure. I don't think today is the day to be saying yes or no."

Cronk wrote himself into NRL folklore when he played through the pain of a 14cm break in his collarbone during the Roosters' grand final win over former side Melbourne.

Tricolours doctor Ameer Ibrahim described it as the most heroic thing he'd seen while coach Trent Robinson called it the stuff of legends.

Suggestions abounded Cronk would hang up the boots after the first year of his two-season deal with the Roosters - having delivered the premiership trophy he was brought to Moore Park to win.

Cronk said there had been no complications after having a plate inserted in his shoulder.

He will report for pre-season training in the new year and be fit for round one's blockbuster against South Sydney.

"It takes around 10 weeks to completely heal," Cronk said.

"But the surgery fast-tracks it, reinforces it. If I had of retired and wasn't playing contact sport, they would have let it heal normally. Just to reinforce the bone they put some plates in.

"From what I know it's stronger. I might actually make a few tackles next year."

Australian Associated Press