AFL Players Association boss Paul Marsh has hit out at the league's last-minute consideration of an injury substitution for the 2021 season.
Just two days out from the season-opener, the AFL is still weighing up whether to introduce a 23rd player to be included in a team's squad.
An announcement was expected on Tuesday but that will be pushed back until at least Wednesday after a planned meeting with the 18 clubs' footy bosses was delayed.
The idea originated due to concussion, after the league in January tightened rules around medical head knocks, but there has been a push for the substitution to be activated for any game-ending injury.
Marsh said the AFLPA's leaders were indifferent to an extra player being used but felt as much as possible needed to be done to protect players from the long-term effects of concussion.
"Concussion, which was where this started, is a very serious issue so the steps we take to minimise the risks are really important," Marsh told SEN.
"Players, ourselves (AFLPA), even coaches that I've spoken to in the last couple of weeks, are pretty frustrated at this process.
"This was a foreseeable problem when the rule changes were made last year around rotations, the man on the mark rule and the return to normal quarter lengths.
"On the eve of the season we're just putting a Band-Aid on an issue here that could have been dealt with earlier."
Collingwood coach Nathan Buckley is backing an "unencumbered" substitution rather than it being used only for concussions.
"The coaches met last week and we were unanimous in seeing it as a positive which would support fairness and improve performance," Buckley told reporters.
"We were all concerned about the possibility if you lost a player early with low rotations and higher game time that potentially would have a greater impact than ever to be a man or two down."
If an AFL player is deemed to have a medically diagnosed concussion they will now automatically serve a 12-day break.
Concussion has become a hot topic, not just in the AFL but across world sport, with greater research uncovering the significant debilitating effects head knocks can have on the brain.
Geelong legend Graham 'Polly' Farmer, St Kilda great Danny Frawley and former Richmond midfielder Shane Tuck were all revealed to have been suffering from CTE (chronic traumatic encephalopathy) before their deaths.