The AFL is facing pressure to abolish the substitute, with the players' association backing Essendon coach Brad Scott's call to help ease pressure on doctors making concussion assessments.
It comes after three clubs were issued with please explains by the AFL following incidents relating to head injury assessments last weekend.
The league moved on Thursday to allow football managers to receive immediate notifications about when players need concussion tests.
"This will assist in ensuring that the most serious incidents that require the immediate removal of the player for off-field assessment (including SCAT6) are appropriately prioritised and actioned," the AFL statement read.
"The AFL will review the current protocols at the end of the year, including continued evaluation of introducing independent doctors at matches and any further potential improvements."
Scott, a former AFL football operations boss, wants the league to ditch the sub rule and move to five players - 23 overall - sitting on the bench instead.
The AFLPA has come out swinging to back him up, noting players had "never been in favour of the sub rule", and it caused "another layer of unnecessary stress" to their jobs.
Brett Murphy, the AFLPA's head of player relations, said the current cohort are "strongly" behind abolishing the sub from next season.
"As we saw on the weekend, we have seen multiple examples of players subbed out of games while such checks are made, impacting both the player and club," Murphy said.
"It also has the effect of putting doctors in the difficult position of making a quick assessment to enable a decision to be made, something we certainly don't want to see given the importance of appropriate medical care.
"None of this would be an issue if the substitute was simply added to the bench.
"We have asked the AFL to review its position on the sub rule, and seek further feedback from clubs, before making a decision for next season."
Carlton have been slapped with an official reprimand by the AFL due to the club's handling of star forward Harry McKay's head knock.
McKay remained on the field for several minutes against North Melbourne on Sunday despite him appearing dazed and confused.
The powerful left-footer managed to kick a goal before he left the field to have a HIA and was eventually cleared of concussion.
The AFL would have taken further action against Carlton had their club doctors not been taking care of injured players Blake Acres and Sam Durdin when McKay's head hit the ground.
"Whilst the club was in breach of protocols on account of the short delays in removing McKay from the field, the AFL acknowledges the club's explanation predominantly on account of Carlton's doctors dealing with multiple pre-existing and concurrent injuries," an AFL statement read.
Carlton coach Michael Voss was "comfortable" with how the club handled the situation, with McKay set to play against Port Adelaide on Friday night.
Adelaide have been cleared of how they treated Jordan Dawson's concussion last Friday night against Essendon.
Medical spotters did not require Dawson to leave the field, but the Crows captain was later placed in the concussion protocols and he miss Adelaide's clash with Hawthorn this Sunday.
The AFL is still investigating the circumstances surrounding Brisbane Lions star Harris Andrews, who has been ruled out of the QClash on Saturday with concussion despite returning to the field last Sunday against Sydney.
The AFL's club doctors released a joint statement on Wednesday, calling for all on-field HIAs to be banned.
Lions coach Chris Fagan believes it is a "messy process" that needs "tidying up" by the AFL.
"There needs to be a better way to communicate things on field, so decisions can be made more quickly," Fagan said on Thursday.
" ... Why can't somebody who is watching the game and sees the vision talk to the umpire and say, 'stop the game, that guy needs to come off'.
"That would take a lot of unnecessary investigations, inquiries, fines, all those things out of it."
North Melbourne coach Alastair Clarkson said the Kangaroos hadn't formed a position on the sub, but joked Scott should have changed the rule when he was working at the AFL.
