The New Zealand Warriors may be down a key man for their season-opener, with Charnze Nicoll-Klokstad in doubt.

The star fullback, who was a key part of the Warriors' push to the 2023 preliminary final, is set to retain the number one jumper in Andrew Webster's squad this year despite the arrival of Roger Tuivasa-Sheck.

The former Dally M Medalist returns to the Warriors after a stint away in rugby union, and while he has prepared for the campaign in the centres, he could well find himself at the back for Round 1 if Nicoll-Klokstad is unable to play.

That comes as the New Zealand Herald's Michael Burgess reports coach Webster confirmed Nicoll-Klokstad is in doubt during his media conference on Tuesday morning.

The Warriors still have two weeks before their season-opener, when they play the Cronulla Sharks at home in Auckland on Friday, March 8. They follow their opening game of the year up with a difficult trip to Melbourne to play the Storm, a game they will be desperate to have Nicoll-Klokstad fit for, before back-to-back home games against the Canberra Raiders and Newcastle Knights in Rounds 3 and 4.

Tuivasa-Sheck isn't the only option to play fullback if Nicoll-Klokstad is out in Round 1 though for the Warriors, with Taine Tuaupiki the other likely option. The 24-year-old made his debut in Round 3 last year and went on to play five games, impressing in all of them.

The rising star could allow Tuivasa-Sheck to stay at his pre-season training position in the season-opener by adding to his five first-grade games.

Tuaupiki played against the Wests Tigers in the club's opening trial on Sunday in Christchurch.

If the Warriors do opt for Tuivasa-Sheck at fullback however, there are a number of options to come into the centres, with one of Rocco Berry and Adam Pompey already likely to miss out, and young gun Ali Leiataua also pushing for minutes in the top grade this year.