The AFL has handed Port Adelaide a $100,000 fine following the club's handling of Aliir Aliir's clash with teammate Lachie Jones during last week's loss to Adelaide.

The league spent the last five days investigating the matter after Aliir was cleared to return to play following a head injury assessment. Port Adelaide's club doctor did not have Aliir undergo a SCAT5 concussion test following the HIA.

Jones was subbed out of the Showdown match, however, was diagnosed with a migraine.

On Monday, Port Adelaide placed both Aliir and Jones in concussion protocols following a 'please explain' from the AFL, who have now handed down a six-figure fine to the South Australian club.

The AFL confirmed on Friday that $50,000 of the $100,000 fine would be included in Port Adelaide's football department soft cap as punishment for the incident. The remaining $50,000 will sit outside of the cap unless the Power commits a similar breach of concussion protocols before the end of the AFL and AFLW seasons in 2024.

"The AFL Concussion Protocols are some of the most stringent that exist in world sport, however they require strict and consistent adherence to protect the health and safety of our players,” AFL General Counsel Stephen Meade said in a league statement.

“In this instance Port Adelaide admitted that Aliir should have undergone SCAT5 testing at the time immediately following the collision on Saturday night. By not undertaking the test, and Aliir returning to the game without being subject to that further detailed assessment, Allir's wellbeing was potentially at increased risk.

“The health and safety of all players is paramount, and this will continue to be the focus for our clubs and for the AFL.

“AFL Club doctors are some of the most accomplished sports medicine professionals in the world, they have intimate knowledge of their players, and while in this instance there was an error in the club's process, it shouldn't undermine the work our club doctors undertake, and the care shown to everyone at their football clubs.

“I would like to acknowledge the cooperation of Port Adelaide Football Club regarding this incident and the pro-active approach from the club in assisting the AFL in this matter and the planned further review.”

The AFL has confirmed it will also conduct a further review of the incident to identify learnings for PAFC and the broader industry noting the AFL and AFLW Concussion Management Guidelines are reviewed and updated annually.

Port Adelaide have accepted the sanction handed down from the league, with football boss Chris Davies admitting the club made a "significant mistake".

“Our club understands the health and safety of players at all levels of the game is the key priority and we understand concussion and the protection of the brain health of all those playing our game is paramount,” Davies said in a club statement.

“As we said publicly earlier in the week, we accept we made a significant mistake in not following the concussion guidelines appropriately. Our club doctor owned the mistake and publicly acknowledged his error.

“We accept the penalty handed down by the AFL and now look forward to cooperating with AFL chief medical officer Michael Makdissi to review the weekend's incident to ensure all our club medical officers are fully cognisant of the AFL's expectations regarding the concussion guidelines.”

Port Adelaide will be without both Aliir and Jones for this weekend's clash with Geelong after the pair entered the AFL's mandatory 12-day concussion protocols period.