Port Adelaide Football Club chair David Koch has issued a call for SA’s two AFL clubs to work together to take the “nastiness” and “sting out the Showdown”, after last weekend’s match was marred by incidents both on and off the field.

The Adelaide derby is always an intense encounter — but Saturday’s clash between the Crows and the Power produced multiple controversies, including a head-high hit to Crows star forward Izak Rankine that led to a melee.

Port defender Dan Houston has been handed a five-week suspension, which the club will be appealing on Thursday.

It has since been revealed police are investigating claims that Crows midfielder Matt Crouch, while walking off the ground, knocked the cap from a fan’s head.

“Police are investigating the report of an assault that occurred at the Adelaide Oval at the conclusion of the Showdown,” police said.

“Police are aware of videos circulating on social media which appear to relate to the incident and ask if anyone has information to call Crime Stoppers on 1800 333 000.”

Crows coach Matthew Nicks on Wednesday said he cannot comment on the alleged assault because of the investigation but said Crouch has the club’s “full support”.

‘Nasty edge’ destroys it for everyone: Koch

Off the field, the atmosphere was charged well before game day, after Crows young gun Josh Rachele sledged opposition fans during the lead-up, telling commercial radio stations Nova and FiveAA last week that Power supporters “don’t have many teeth”.

Rachele followed up on the comment after scoring a goal during the game by running towards Power fans and pointing at his grinning mouth.

The aftermath of the match has led to revelations of racist comments on social media targeted at Power forward Willie Rioli, and allegations the club’s mascot Thunda was punched, leaving the person in the suit with a bleeding nose.

During an interview with radio station FiveAA, Power chair Koch said he and former Crows chairman Rob Chapman had for years worked closely together to “take the nastiness out of the Showdown”, and that there was evidently a need to renew that going forward.

“A whole range of things means we’re going to have to really look at something before the next Showdown — both clubs — to take a responsibility for just taking the sting out of the Showdown, the nastiness out of the Showdown,” he said.

“You can’t punch a mascot, you can’t racially vilify a player online.

Koch said “good old-fashioned banter is one thing”, but suggested the on-air conversation in which Rachele’s conversation was made was “sort of really elitist crap, denigrating, almost poor-shaming”.

Nicks said he has spoken with Rachele and as a team, they have hoped to improve and “be mindful of doing the right thing”.

“It wasn’t us one individual player, it was us as a team and areas we have got to be better in,” he said.

“You can get it wrong occasionally and I think this week’s one where you look at and go, ‘Listen, there’s some bits we’ve got to improve on’.”

Nicks said the most recent Showdown was “a huge game” and had “an intensity” where Port was gunning for finals.

“The intensity I think we all enjoy and love. When adrenaline is pumping and emotions are high, sometimes we can overstep the line,” he said.

“I think everyone loves Showdowns and we’ll just continue to work on where that line is.”

Nicks said putting up barriers to protect players walking off the field could mean losing interactions with fans.

“The reason that we allow fans close to the boundary line is for those kids that just love footy,” he said.

“They have idols and they have heroes and they want to come down and get amongst it.

“If we start putting up barriers and fences, then we lose that.”

The Crows coach said Rankine has been recovering well and “in really good spirits” despite concerns on Saturday night.

He said in a post-Showdown chat, Port coach Ken Hinkley had wanted to check on Rankine “first and foremost”.

“With respect, I don’t care what the punishment is, it doesn’t interest me. I’m interested in our players, their welfare and their health,” Nicks said.