Both Richmond and Carlton implemented the new rule.

Steve Hocking, the AFLs general manager of football operations, has given the tick of approval to how the medical substitution rule was implemented on Thursday night.
Both Richmond and Carlton used their subs in the 2021 season opener, with Jack Ross replacing the crocked Nick Vlastuin for the Tigers, and Oscar McDonald stepping in for the injured Jack Silvagni for the Blues.
Both subs had a positive impact for their respective sides as the Tigers edged away late to beat the Blues by 25 points at the MCG and both sides implemented the rule well, according to Hocking.
I had a front row seat as to how it was all implemented, he said on SENs Dwaynes World.
Ive only got complimentary remarks to make about how both the clubs instituted it last night.
Regarding the respective knee and shoulder injuries sustained by Vlastuin and Silvagni, the AFLs footy boss says scans will be taken into account by the independent medical officer when assessing the players for next weeks games.
Thats part of the process, he added.
Theres those avenues and theres a range of other things. Thats a process that (Dr) Peter Harcourt will look into during the week.
As we do, weve got MRO and umpiring reviews as well, that will all happen early in the week.
Hocking further outlined his faith that clubs will not be able to exploit the rule for their own benefit, with many criticising the malleable nature of the rule.
Weve got trust in our doctors and weve got the right processes in place to address whatever may come out of the medical sub, he said.
I come back to the fact that I saw it in full operation last night. Ill get another look at it tonight (at Western Bulldogs v Collingwood) and as I said openly, well just continue to monitor it as we need to and review it as we go along.
Ive got confidence in our doctors and the broader industry.
Listen to the full chat with Hocking below: