Warriors coach Nathan Brown doubts the new 18th-man policy will be necessary.
The NRL plans to introduce the extra player as an injury replacement when a team has lost three members to concussion.
The reserve will be an emerging player.
Brown told D'Arcy Waldegrave he's unsure whether it's needed.
"You had three concussions for one team, I personally think they’re wasting their time bringing that rule in."
The Warriors face the Roosters on Sunday.