Jy Simpkin's spirited defence of teammate Paul Curtis has earned the former North Melbourne captain an AFL warning.

Simpkin heeded an AFL request to take down his social media posts after Tuesday night's tribunal hearing, where Curtis' three-week rough conduct ban was upheld.

It was similar to earlier this week, when the league's football operations boss Greg Swann rang Damien Hardwick after the Gold Coast coach vented about some umpiring decisions during their away loss to Geelong.

Rather than a "please explain" or a fine, Simpkin and Hardwick have been put on notice by head office.

"The AFL needs to get it together, the constant rule changes and the MRO (match review officer) is laughable," Simpkin had posted.

"Players don't know what they can and can't do anymore. Just hope for the best each week".

Curtis was banned for a tackle that left West Coast player Hamish Davis with concussion.

Simpkin compared Curtis' fate to Hawthorn forward Mabior Chol, who was not suspended for a tackle last season that left Geelong defender Tom Stewart with concussion.

It is understood the AFL will use next week's two-day conference with club chief executives to warn against commentary on the tribunal or umpiring.