"He may play a part tomorrow," said Warriors nines coach Steve McNamara. "The doctors and the physios are working hard and hopefully we can get a positive result on that."
Johnson's absence will provide a strong test of the tournament's credentials in the eyes of local punters, and while the Warriors have previously felt some obligation to play their big names they won't be taking undue risks with a long NRL season ahead.
"From day one we've made it clear we're really preparing for an NRL competition and some other teams are in the same position as us going into this tournament," said McNamara.
"Because we're the home team it does make it a little bit more difficult for ourselves. But sometimes you have to make tough decisions based on what was right for our own squad and for our own team going forward.
"If Shaun's available and fit then we'll give him that opportunity. But if he's not we'll have to make another strong decision tomorrow."
The Eels and Sea Eagles are assured of quarter-final spots but who they play will be determined by the outcome of the final round Waiheke pool clash between the equally impressive Panthers and Titans. Both the Bulldogs and Sharks are out of the finals race after the two Sydney clubs endured twin defeats for a fruitless day.
In the Rangitoto pool, Brisbane are outright leaders after back-to-back wins over Melbourne and Newcastle, with the latter two teams set to fight it out for the second finals berth after registering a win apiece, while Wests Tigers effectively bow out after losing both their games.
But it's the Thurston-inspired Cowboys who are setting the pace overall and dominating the Hunua pool, having racked up 12 tries in impressive style, crushing the Roosters 27-15 and romping home 35-6 over Canberra.
The winners of the inaugural 204 tournament will look to maintain a perfect pool record tomorrow when they meet the winless Rabbitohs, while the Roosters and Raiders will duke it out to decide the group's second finalist.
Meanwhile, The Kiwi Ferns women's side went down 20-4 to the Australian Jillaroos in the first of three transtasman encounters.
The home side fell behind 12-0 with the visitors scoring two runaway tries before striking back with a lone try early in the second-half.
It wasn't enough however with the Jillaroos adding two more four-pointers to cap an impressive display.