THE AFL has written to clubs warning them that public commentary about umpiring will be closely monitored after Tigers coach Damien Hardwick and Melbourne ruckman Max Gawn were outspoken on the standard of officiating last week.

Hardwick claimed Geelong's home crowd influenced umpiring decisions during the Tigers' 14-point loss to the Cats at Simonds Stadium last Saturday.

After giving away five ruck interference free kicks against St Kilda on Sunday, Gawn tweeted a picture of the Laws of the Game booklet with the caption: "Some light reading this week". 

The AFL's acting football operations manager Andrew Dillon wrote to clubs on Thursday reminding them that negative commentary about umpiring would not be tolerated.

"Over recent months there have been several public comments made by senior AFL coaches and players that have related to AFL umpiring performance," Dillon told

"Whilst it should be noted that each individual issue has been managed directly between the AFL and the relevant club, I would like to take this opportunity to remind all AFL club coaches, players and staff of their responsibilities under the AFL regulations." 

"It should be noted that any public comments made going forward may be subject to sanctions." 

AFL rule 14.1 (public comments on umpires) stipulates: "Any person subject to these regulations or AFL rules, shall not make any public comment about an umpire or a decision made by an umpire".

"Where a person contravenes this regulation, the person's club shall be liable to a sanction." 

Players and coaches can be fined up to $20,000 for a first offence and as much as $100,000 for a second or subsequent offence. 

It is understood the League spoke with both Richmond and Melbourne about Hardwick and Gawn's comments reminding them that such commentary could lead to a sanction. 

Melbourne received an explanation from umpires coach Hayden Kennedy about the free kicks paid against Gawn, and coach Simon Goodwin said on Friday the club had more clarity on what constitutes a ruck infringement. 

"That's what the open dialogue with the Umpires' Association is all about, to get some clarity,” Goodwin said. 

"Clearly Max hasn't had that throughout a game before in the last three years. 

"Once you see that, you want to get some clarification and we've received that.

"We're more than comfortable with how it's being umpired."

In June, Geelong coach Chris Scott and St Kilda counterpart Alan Richardson were critical of an umpire for a controversial play-on call on North Melbourne midfielder Shaun Higgins in the Kangaroos-Western Bulldogs round 14 clash.