FREMANTLE coach Ross Lyon says he's so confused about how AFL umpires are interpreting the game that he no longer knows what's a free kick.

Lyon has been left particularly confused over a perceived relaxing of the chopping of the arms rule, and also the growing trend of players jumping on each other in congestion.

"My interpretation is umpires are letting the game go," Lyon said on Wednesday.

"There have been free kicks that were being paid last year that aren't being paid this year.

"The saddle's back. People are being jumped on on the ground, being ridden and jumped on by two or three, and the ball can't get out.

"Clearly they'll blow for the ball-up, but they're not paying the obvious free kicks, hence the term the 'rolling maul'.

"And the amount of arms that are being taken out, chopping arms ... to be honest I don't know what a free kick is or isn't anymore."

Fremantle will be aiming to bounce back from last week's loss to the Sydney Swans when they host North Melbourne at Patersons Stadium on Friday night.

More to come ....