PORT Adelaide has been fined $20,000 for failing to follow AFL regulations when assessing Hamish Hartlett after he received a head knock during last Thursday night's game against Hawthorn.

Although Hartlett passed the SCAT3 test and was deemed fit to play, he should have been off the ground for a 15-minute exclusion period to allow the club doctor to access vision of the incident.

Instead, Hartlett returned to play after just five minutes because Port Adelaide failed to notify the AFL's interchange official that a head injury assessment was being undertaken as required under the rules.

Notification would have ensured Hartlett remained off the ground for 15 minutes.

Half of the $20,000 fine has been suspended until the end of 2018, with football operations manager Mark Evans saying he took several factors into account when handing down the decision including the following facts:

- The club's chief medical officer was occupied with Brad Ebert who had injured his ribs earlier in the game;

- Elements hindered a video review of the incident;

- Hartlett passed the test; and

- Port offered to review its processes in relation to assessing head injuries.

Hartlett played out the game without further incident following the knock, conducted a television interview at half-time and has been selected to play against North Melbourne this week.

Power coach Ken Hinkley said the mistake was simply a case of the club momentarily forgetting the strict procedures associated with informing the League of concussion tests.

"There was no risk, there never has been, you know what I'm like with player welfare - we don't take any risks in that space," Hinkley said on Friday afternoon.

"But we lost our way a little bit with procedure.

"It wasn't deliberate but we didn't get it right.

"We all have responsibilities and I play a part of that on game day … we all share that responsibility."

Port released a statement on Friday accepting the penalty, saying the club had erred in failing to notify the interchange steward that the assessment was being undertaken.

"If we had followed that protocol, Hartlett would have been excluded from play for longer so vision of the incident could be reviewed," said football manager Chris Davies.

"Despite this issue of timing, Hamish was cleared of concussion at the time and has shown no sign of concussion during subsequent testing throughout this week."

"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."