A concussion memo sent by the AFL with regards to pre-season head injuries has sparked "confusion and frustration" among clubs.
The Age reports, the AFL placed all 18 teams on a "concussion ladder" based on head injuries suffered during pre-season training.
The memo stated match simulations produced the highest rate of concussions and included 'individualised reports' outlining each club's rate of pre-season head injuries.
Clubs are said to be frustrated by the move and the lack of clarity on how to properly protect players, as well as the fact there was "no conclusive evidence linking a certain amount of contact training with a reduction in concussions."
According to the report, one club's data showed a larger amount of contact drills were being conducted, but for fewer overall concussions.
Tom Lynch stumbled off the Punt Road training track after a heavy knock. Twitter
Port Adelaide chairman David Koch is said to be among the most vocal in his dissatisfaction.
It comes as limiting the amount of contact training sessions both in the AFL and AFLW has been a point of emphasis for officials but there has been no restrictions for clubs this preseason.
"Player health and safety and the reduction of concussion and head impact injuries is at the forefront of decision making at the AFL and we are currently working closely with clubs to understand the levels of contact training being undertaken throughout the year," a league spokesperson said.
"The gathering of this information is still ongoing."
Several concussions have already been recorded this preseason, with Richmond's Tom Lynch, West Coast star Harley Reid and Melbourne youngster Matthew Jefferson all forced to sit.
Nathan Murphy, Angus Brayshaw, and youngsters Aidan O'Driscoll and Josh Carmichael were all forced to medically retire out of the game due head knocks.