The 33-year-old’s deal runs out after the Rugby World Cup and it has previously been rumoured he could return to rugby league or take up a coaching role.
And the two-time Rugby World Cup winner, who has also had seven professional fights in boxing, is undecided on his Blues future beyond the 2019 Super Rugby.
When asked by the New Zealand Herald if this campaign will be his last with the Blues, he answered: “It could be, bro, it could be.
“If I did finish at the end of the year, as long as I competed every day and put my best foot forward as a person and a player, I’ll be happy.”
Williams has endured several injury issues over the past couple of years, but he hopes the worst is behind him ahead of a World Cup year.
“For the last two years I’ve been so methodical with my planning and preparation,” he said. “Every off-season: ‘A, B, C, D and I’m going to get to E’.
“It starts here with the Blues. I want us to have a successful year. I want the boys to succeed.”