Essendon coach Brad Scott has called for the AFL to abolish the sub as a way to alleviate pressure on doctors making concussion assessments.
AFL club doctors are pushing for on-field head injury assessments to be banned and want league medical staff to instead rule on concussions during a game.
The AFL Players' Association has also called for players to be removed from the field to assess significant head injuries.
Scott and Sydney coach John Longmire want HIAs to be treated in the same fashion as the blood rule, with play stopping immediately.
But Scott, a former AFL football operations boss, is adamant the league ditch the sub rule and move to five players sitting on the bench instead.
In Friday night's heartbreaking defeat to Adelaide, Essendon subbed important midfielder Jye Caldwell out in the final quarter while he underwent a HIA.
Caldwell subsequently passed the concussion test and could have returned to the field late in the three-point loss had he been available.
"The frustration is we want to give the doctors the best environment to assess players, and that's off-the-field," Scott said on Wednesday.
"People would say we didn't have to activate it (the sub on Caldwell), but common sense would say we did.
"If you really want to take the pressure off the doctor abolish the sub, there's just no reason to have it.
"Have five on the bench and then clubs don't get disadvantaged, the pressure is off the doctors and they can take their time to make the assessment and you're not making decisions on subbing players in or out."
Scott left his job at the AFL in October 2022 when he was appointed Bombers coach.
The former North Melbourne coach believes some clubs will advocate to keep the sub beyond this season.
"I can tell you with absolute certainty that they're saying that because they think it suits their purpose for whatever reason," Scott said.
"I don't think five on the bench helps us, hurts us much, either way.
"It's just to me what's best for player welfare and player safety."
Western Bulldogs coach Luke Beveridge called it a challenge to decide when a game should be paused for an injured player.
"I think it should be stopped, but how do you know when it should be?" Beveridge said on Wednesday.
"If we get to the point where we can stop it, somehow work out that there's a player who needs to come off because he's had a head knock, that would be perfect.
"But I don't know how we do it."
Geelong star Jeremy Cameron refused to come off the ground to be assessed in the final quarter of the Cats' tight round-nine match against Port Adelaide after his head slammed into the ground.
Despite playing out the match, Cameron was the next day placed into concussion protocols, prompting questions of Geelong and the AFL.
League boss Andrew Dillon cleared Geelong of any wrongdoing and ruled out bringing in independent doctors.
Cameron admitted every head knock was different and they were hard to judge immediately.
"If it meant that I have to get off the field then yeah, I would abide by those rules and go sit on the bench and take it from there," he said at Marvel Stadium on Wednesday.
"Because I've had a couple (of concussions) now, I reckon when you're in the first half of your career you just want to attack the ball, you want to smash in as hard as you can ... when you've had a couple of concussions you realise just how important it is to get right."
AFLPA acting chief executive Regan Bunny said her organisation shares the concerns raised by the AFL Doctors' Association in relation to the difficulties in assessing players on the field for potential head injuries.
"It's critical that medical intervention, assessment and potential treatment occurs in an environment that allows doctors to effectively evaluate the people under their care," Bunny said.
"If this means temporarily stopping the match by officials or umpires to safely remove players in this situation, we are open to exploring this with the AFL and the AFLDA to understand the practicalities of doing so."
