However Hoffman confirmed he had no plans to retire, and was looking forward to his 16th season of senior league in 2018.
"I'm keen to play again next year and I'm looking forward to pulling the boots on somewhere," said Hoffman, who added he had options open between the NRL and Super League.
"I'm not ready to finish playing [and] I still think I have got quite a bit to offer."
Hoffman had a mixed 2016 season.
He didn't reach the heights of his first year at Mt Smart - where he was consistently one of the best on the park - and his form dipped in the second half of last year.
Hoffman said coach Kearney delivered the news a week before the public unveiling of Tuivasa-Sheck.
"Steve called me into his office, sat me down and told me straight up," said Hoffman.
"That is all you can ask for. It was [a surprise] - anytime you are told you are not going to be captain, or the club is going in a different direction.
[But] it won't change anything I am going to do on or off the field this year."
Hoffman also backed Tuivasa-Sheck's elevation to the top job.
"[He will be an] extremely enthusiastic captain," said Hoffman. "[He's a] young bloke, very excitable. Bit of a different captain to what I was, that's something the group needs."
"I told things the way they were at certain times last year and I'm sure Roger will be really positive about the way he goes about. Maybe it's a generational thing."
Tuivasa-Sheck is expected to play at least the first half on Saturday, in his first match since the season-ending knee injury suffered in round seven last year.
Such a return is always a nervy time - everybody remembers what happened to Ben Henry - but Tuivasa-Sheck is confident he is ready for the rigours.
"It's all about the practice," said the 23-year-old. "We did a full contact session [on Wednesday] and the more practice I do here then come round one I should be sweet."
