Sydney star Isaac Heeney is certain to come under AFL match-review scrutiny for an incident that could doom his Brownlow Medal chances.

Heeney was playing forward in the third term of Sunday's upset loss to St Kilda when he went to fend off opponent Jimmy Webster.

He caught Webster in the face and Heeney's body language immediately afterwards was that of a player who knew he'd made a mistake.

Webster was on his haunches for a few seconds, while Heeney took an easy mark and kicked a goal.

The Swans star ran over to Webster and there was no bad blood between the pair.

Saints coach Ross Lyon also was unperturbed by the incident.

"He certainly didn't mean to clock Webster, but he accidentally clips him in the head," Lyon said.

"He's a great player and certainly there was no intention."

Heeney was in the top rung of Brownlow betting before Sunday's incident.

Also on Sunday, in-form Adelaide star Izak Rankine bumped an unsuspecting Brandon Starcevich off the ball, forcing the Brisbane defender out of their game with concussion.

Rankine lined up Starcevich as the pair were retreating from a stoppage, his body check flooring the Lions hard man and putting him out of the Gabba contest at quarter-time.

"The judiciary will have a look at that I've got no doubt, and judging by crowd reaction it can't have been all that good," Lions coach Chris Fagan said.

Heeney and Rankine will learn their match-review fate on Monday afternoon.

Also on Sunday, Port Adelaide suffered a blow ahead of their important AFL clash against Gold Coast, with in-form forward Mitch Georgiades hit with a one-match ban for striking.

But GWS can breathe a sigh of relief after captain Toby Greene was charged with the same offence and escaped with a fine.

Greene can accept a $3750 penalty for his blow to Carlton defender Brodie Kemp's chest during the Giants' 12-point win at Engie Stadium on Saturday.

Georgiades was charged over an off-the-ball incident involving Western Bulldogs player Nick Coffield, putting a dampener on the Power's 48-point win on Saturday at Adelaide Oval.

His actions were assessed as intentional conduct, low impact and high contact.

Port are yet to confirm whether they will challenge the ban.

Goergiades kicked five goals against the Bulldogs, taking his tally to 27 in 13 games this season on return from a ruptured anterior cruciate ligament.

Sitting sixth on the ladder, Port play 12th-placed Gold Coast at People First Stadium on Sunday.