Richmond premiership forward Jack Riewoldt was concussed after Carlisle's clumsy and late attempted spoil during the first quarter of Saturday's clash at the MCG.

AFL match review officer Michael Christian assessed the incident as careless conduct with high impact to the head.

The Saints have until 11am on Tuesday to launch a tribunal challenge but coach Alan Richardson has hinted they will seek to have Carlisle's ban downgraded to one game.

"Our gut feel was that it would be a week," Richardson told Fox Footy's AFL360.

"I think the players have always got a really good feel for this. No one remonstrated with Jake - it was a clumsy accident that got him high.

"We were a little bit surprised with two (games) so that's the conversation that we'll have."

Richardson noted the incident was similar to Josh Caddy's round-two hit on Adelaide's David Mackay which landed the Tiger a one-game ban.

"If we go that way, that'll be the argument," Richardson said.

"There's been a precedent where a similar outcome, a player concussed ... (his) intent was to go for the ball but he hit him in the head."

Christian said the fact that Riewoldt was unconscious before he hit the ground was a factor in his finding.

"Three things we talk about with respect to impact are the visual look of the blow, the player's reaction and the medical report," Christian told reporters.

"Certainly that look wasn't great and was part of the reason it edged up into high impact."

West Coast youngster Willie Rioli was fined for tapping umpire Ray Chamberlain on the backside during the Eagles' win over Hawthorn at Etihad Stadium.

Rioli gave away a 50m penalty for dropping his knees into the back of a prone Blake Hardwick late in the first quarter of Sunday's game, then gave Chamberlain a friendly pat while running back to his mark.

A grading of intentional conduct would have seen Rioli sent straight to the tribunal, following in the footsteps of four other players in recent weeks.

"Rioli wasn't looking at the umpire when the contact was made and we thought the best grading was careless," Christian said.

Geelong's Tom Hawkins and Carlton's Ed Curnow each received one-game bans for intentional umpire contact earlier this month, while Curnow's brother Charlie and Gold Coast co-captain Steven May were fined for careless contact.

Rioli also copped a $1500 fine for misconduct against Hardwick.

Nine players received fines, including Richmond superstar Dustin Martin for misconduct against St Kilda's Jimmy Webster.

Australian Associated Press