The sub could be returning in 2021...
"THE AFL is strongly considering a request from some coaches to use a substitute player to replace a concussed teammate in 2021 matches.
The mooted change would need to be officially approved by the AFL Commission before Thursday's night's Richmond-Carlton season-opening match at the MCG.
Coaches have asked for a additional 23rd player to be the concussion sub. Currently, each team is comprised of 18 on-field players and four interchange."
If it does come into effect here's hoping that the 23rd player is named when the teams are announced the day before, not when final team lineups are announced 45 mins before the game..
Also, I wonder what it will mean for SC. Would the 23rd player's score only be counted if they are subbed on? Otherwise they just count as a DNP. You would think that would be the case..
https://www.afl.com.au/news/561189/coaches-concussion-worry-sparks-push-for-23rd-player