The AFL is investigating four Port Adelaide players for a potential breach of coronavirus protocols for not wearing face masks while spectating at the Olympic swimming trials in South Australia.

Vision emerged on Friday of Zak Butters, Ollie Lord, Dylan Williams and Mitch Georgiades sitting in the stands at the swimming event on Thursday night - without masks on - while others around the four players were covered up.

Event protocols meant spectators must wear masks while seated unless they were eating or drinking.

AFL football boss Steve Hocking said on Friday that the potential breach was being “worked through” with the club.

“It’s a really important reminder, whether it be in the community or you’re sitting in the stands at a swimming meet, just remember the care and duty we’ve got in following government guidelines,” Hocking said.

It has been pointed out that the players were not representing the club at the time, which could ease any potential sanction.

This comes after Adelaide was this month handed a $50,000 fine from the AFL after players had breached coronavirus rules by not wearing masks on an aeroplane. The fine was included in the Crows’ soft cap for next season, and will have an impact on football-department spending at a time when the cap has already been slashed.

The Power will face the Gold Coast Suns at Metricon Stadium on Saturday.

The AFL is also continuing to investigate Hawthorn because of a boxing session gone wrong when Mitch Lewis was knocked out and concussed when sparring with Jacob Koschitzke. Players were not wearing protective headgear at the time, a point of concern at a time when head knocks and concussion are a growing threat to the sport.