The Rugby League World Cup Golden Boot will be announced in Brisbane on Thursday, three days before the final at Suncorp Stadium.
That schedule rules out performances in Sunday's decider, a decision former Dragons and Sharks coach Shane Flanagan called "crazy."
"It's probably out of those two [Ponga and Walsh], they'd be the favourites, but we're gonna pick it before the game - I think it's crazy," Flanagan told Triple M.
"If we're gonna pick a player before this match, it could leave you with egg on your face.
He argued that a strong final could make a pre-match choice look wrong, especially if one of the two fullbacks scores several tries and is named player of the match.
Australia's Reece Walsh and New Zealand's Kalyn Ponga are widely viewed as the leading candidates for the Test player of the year honour.
Walsh's semi-final hat-trick against Samoa helped Australia reach the final, while Ponga returned from a broken arm suffered in New Zealand's opening loss to Australia.
Ponga then inspired a convincing semi-final win over Tonga. The shortlist, announced Wednesday, also includes Tonga centre Robert Toia, Samoa forward Francis Manuleleua and New Zealand youngster Casey McLean.