Vatuvei crossed for his 150th NRL try in Saturday's golden point loss to Canberra before departing with the injury, which is expected to trouble him for the remainder of the season.
The 30-year-old has been named to start against the Panthers at Mt Smart Stadium but the Warriors medical staff will monitor his progress over the next three days.
"I'm pretty confident that it will come right. I've just got to look after it really well, ice it up and get the swelling down, and just hope it stays good for the game," Vatuvei said.
"I've got to make sure I'm 100 per cent. I don't want to go into a game not feeling like that and just coming off, so I've got to make the right call."
The uncertainty around Vatuvei's fitness continues a stop-start 2016 campaign that has seen the Kiwis international play just nine matches.
Earlier this season he missed three games after he was dropped to reserve grade and stood down from test selection for his involvement in the prescription pills and energy drinks scandal, and was later granted leave as he struggled with personal issues.
He came back for the round 13 win over Brisbane, but suffered a hamstring injury against Newcastle the following week that kept him sidelined for three matches. He then returned for back-to-back games against the Sea Eagles and Raiders.
A frustrated Vatuvei said he would test the knee at training and continue to monitor the problem.
"If I feel that I can play the whole 80 I'll put myself in there, but if not I don't want to just play 40 or 60 minutes," he said.
"That's not what my position does and I want to play the full 80. I've just got to do what's right for me and what's right for the team.
"It will limit how much I can train, but there's other stuff I can do to keep myself fit and healthy and make sure I'll be ready.
"I've been in this position before, where it took me up until captain's run until I knew if I was right. I've just got to trust the medical staff and my body and go from there."
Meanwhile, coach Andrew McFadden was coy when asked about the fitness of back-rower Bodene Thompson (ankle) and prop Albert Vete (hamstring), describing both players as "close" to making their returns after two weeks on the sidelines.
Captain Ryan Hoffman indicated Thompson could be back sooner than expected to boost the right-edge alongside halfback Shaun Johnson.
"We've certainly missed him," said Hoffman. "Bunty's [Afoa] done a great job in his absence, but Bodene's a seasoned professional and I know Shaun's going to enjoy having him there because they've formed a really good combination, so it's good to see him back."
- David Skipwith
