THE TRIBUNAL case of Richmond's Rhyan Mansell has key differences from similar incidents in pre-season games, the AFL's chief says.

Mansell will contest a three-game suspension offered by the Match Review Officer at a tribunal hearing on Tuesday night.

The Tigers forward was offered the ban after pushing St Kilda defender Liam O'Connell into a marking contest during Saturday's game in Melbourne.

O'Connell was shoved into the path of Richmond forward Tom Lynch and St Kilda's Anthony Caminiti.

Lynch collided with O'Connell, leaving the Irish-born player concussed and unable to continue playing.

Match Review Officer Michael Christian graded Mansell's incident as careless conduct, severe impact and high contact.

The AFL recently issued a memo to clubs, warning of the dangers of players recklessly pushing other players after a spate of similar incidents in pre-season matches.

But AFL chief executive Andrew Dillon said Mansell's case differed from others incidents which weren't sanctioned by the league.

"The one that's in front of the tribunal today has got a number of key differentiators to the other ones ... and that will play out tonight," Dillon told reporters in Adelaide on Tuesday.

Dillon refused to label Mansell's tribunal as a test case, saying he was reluctant to comment on individual hearings.

"We don't want to necessarily talk here about that individual incident as it's before the tribunal and through the MRO," he said.

"What I will say is that the whole MRO and tribunal process is about protecting the health and safety of our players.

"That has always been the forefront of what we're trying to do.

"So whether it's a test case or not, I think that it now gives the opportunity for Rhyan to put his case forward and we await the outcome."

Richmond will reference pre-season push incidents in defending the 24-year-old in what Geelong captain and former AFL Players' Association president Patrick Dangerfield labelled a test case.

"We've got to be mindful as players, and there's a duty of care there, and you don't want it (pushing) creeping in too much," Dangerfield said on Monday.

"But there is a balance, clearly, as everyone wants to compete, that's what we love about the game, the combative nature. But there's a fine balance with player safety around that.

"So I dare say that's sort of the test case."