Bennell is under investigation by club officials after he interrupted a three-quarter-time huddle between Peel Thunder and Swan Districts on Saturday.

Footage shows the 24-year-old pulling his cousin Traye Bennell aside to speak with him.

It's understood Bennell, who is yet to play a game for the Dockers due to an ongoing calf injury, was later spoken to by Fremantle assistants regarding his behaviour.

Sheahan told SEN Radio on Monday, Bennell's career is all but over at Fremantle.

"Well he's never going to play another game Harley Bennell," he said.

"Apart from his physical problems, he's got soft tissue injuries, and his behaviour is abysmal.

"His wings were wobbly (on Saturday), I wouldn't have liked to see him walk the plank off that ground, and he's had the recent plane episode."

Fremantle coach Ross Lyon said he was "concerned" by Bennell's behaviour after the Dockers' stunning after the siren win against the Tigers on Sunday.

"Of course I'm concerned, I'm concerned about all of my players' welfare," he said.

"He's had an incredibly rough run.

"I'm not here to defend, I'm not here to castigate, I'm really here to say that I haven't got all of the information."

Bennell's curious behaviour during the Peel game, comes weeks after the former Gold Coast Sun was escorted from a Virgin flight to the Gold Coast because he was intoxicated.

In a statement following the plane incident, Dockers' general manager of football operations, Chris Bond, said Bennell had been experiencing "frustration and disappointment" due to his ongoing calf injury sidelining him for the AFL season.

"Due to a recurring injury problem which has prevented him from playing all of last year and now for the next eight to 10 weeks following another setback last week, Harley has been dealing with the frustration and disappointment of not being able to play AFL football," Bond said.

"In the meantime, as a club it is important that we continue to support and provide guidance to Harley on how best to cope with the frustration and disappointment of not playing football."

Bennell has played just one WAFL game since he was traded from Gold Coast Suns at the end of 2015.

With AAP