Hamish Hartlett got a hit to the head during the Power's game against Hawthorn in the Thursday night opener and went to the bench for a concussion test.

He passed the test and returned to the ground five minutes later, but under league rules Port staff should have notified game officials they were doing the assessment and kept Hartlett on the sidelines for 15 minutes.

In a statement, the AFL said the mandatory exclusion period is to give the club doctor a chance to look at video footage of the head knock.

But it acknowledged Port staff had been struggling with patchy wifi on the bench at Adelaide Oval, which had made it difficult for them review passages of play. throughout the game

AFL spokesman Patrick Keane indicated the penalty could have been harsher.

"[The] AFL took into account club was managing another significant player injury (Brad Ebert) in the change rooms at time in deciding penalty," he said.

Port accepted the punishment, with general manager of football Chris Davies saying although the concussion test had been completed correctly, it had been a mistake to send Hartlett back onto the ground so soon.

"The club welcomes the AFL's strong focus on protecting players from head injuries and our medicos' sole concern was for the wellbeing of Hamish throughout the incident," Davies said.

The statement said AFL general manager of football operations Mark Evans said the club's offer to further educate match-day staff about head injury procedures had also been taken into account in deciding an appropriate penalty.

Half of the fine will be suspended until the end of the 2018 season.

The risks of concussion have become a focus for contact sports in recent years, where the National Football League settled a class action law suit taken out by thousands of former players for about $1 billion.

The AFL have gradually introduced stricter guidelines for how the clubs should deal with player concussions, reviewing the rules in 2011, 2013 and 2015.

But head knocks are still taking their toll on footballers.

Earlier this year promising young Brisbane Lions defender Justin Clarke was told by his doctor to never again play contact sport, after suffering a serious concussion in training.

Earlier this week St Kilda youngster Paddy McCartin was taken to hospital with his second concussion of the season.