NRL: Melbourne Storm try-scoring machine Suliasi Vunivalu is racing the clock to be fit for Saturday night's game against Penrith Panthers at AAMI Park.
Vunivalu trained on Wednesday and must pull up well to hold his spot in the extended 21-man squad.
The Fijian flyer was slated to miss three to four weeks with a displaced shoulder joint, suffered in a tackle a fortnight ago against Brisbane.
Storm skipper Cameron Smith declared front-rower Jordan McLean (calf) a more likely inclusion after he was a late scratching last week.
"(McLean) seems fairly confident, but at the same time it's not a given that he's going to be in the side," Smith said.
"We're hoping (to get) at least one back but at this stage I think Jordan McLean would be a better chance."
Christian Welch (concussion) must prove his fitness to stay in the side. The squad will be reduced to 19 with a further cut to be made an hour before kick-off.
Smith admitted Storm must improve on several fronts to keep its unbeaten season intact. A woeful first half last Sunday allowed cellar-dweller West Tigers to score twice before the interval.
"(That's) probably one of the worst 40 minutes that we've put together for quite a while," Smith said.
"The most disappointing part of that 40 minutes was definitely our ball control as well as a few softer efforts in defence.
"It's not what we're known for. They're two areas that we're going to be working on pretty hard this week to improve."
Smith, the new Rugby League Players Association president, revealed mental health and post NRL-career pathways would be a "huge part" of upcoming pay talks with league bosses.
The players want a "fair percentage" of revenue and to be "genuine partners" of the game.
Smith praised NRL chief executive Todd Greenberg for listening to the players with "open ears".