The AFL will investigate claims by recently delisted St Kilda forward Paddy McCartin that he under-performed on pre-season baseline concussion tests to increase his chance of playing later in the year, according to The Age. 

McCartin had told SEN Radio this week, "I've done the testing worse on purpose, so that if I did my baseline again, I'm starting from a worse spot than I would before … I didn't try as hard."

The former number-one draft pick's comments raised concerns for the AFL, with the league's Football Operations boss Steve Hocking set to discuss immediately with chief medical officer Peter Harcourt.

They will also seek clarification from St Kilda, who told The Age there were other factors utilised to measure the effects of concussions during the season.

"The presentation of the player, their daily interaction with club doctors and other staff, along with their response to several levels of testing and exercise, are all used to identify their capacity for training and potential return to playing," a club spokesperson said.

McCartin aims to return to senior footy in 2021, either at his preferred St Kilda, or another club as a delisted free agent.