Nanai originally suffered a high-grade AC joibnt injury during Round 21 against the Parramatta Eels.
He was expected to miss four to six weeks, and a return in Round 25 would represent a relatively quick return to play for the Queensland Maroons State of Origin second-rower, with the club desperate to find a way into the top eight.
Payten, speaking after the club's captain's run, said Nanai had made it through training and was a likely starter for the Sharks game provided he pulled up okay. Payten also confirmed it would mean Coen Hess shifts back to the bench as the side was named on Tuesday.
"He got through training yesterday, so we will see how he pulls up. Every indication though is that he is going to play," Payten said.
"That means Hessy [Coen Hess] will go back into the middle onto the bench, and we have some experience in our middle forwards and a really strong bench."
Nanai, in between suspensions and injuries, has played just 12 games this season, and struggled to hit the form he held during what was a breakout 2022 season.
Scoring six tries and making 96 metres per game, the barnstorming second-rower will need to be at his best in the coming weeks with the Cowboys likely needing to win at least two, and maybe all three of their remaining games against the Sharks, Dolphins and Penrith Panthers to qualify for the finals.
Missing the finals would be a dismal result for Payten's side given they hosted a preliminary final last year and came within inches of reaching the grand final.