The AFL will investigate a fan incident involving Richmond's Marlion Pickett during the Tiger's loss to the Western Bulldogs on Friday night.

Late in the third term, a fan leant over the fence and placed his hand on Pickett's shoulder after the 31-year-old had chased midfielder Marcus Bontempelli deep into the Dogs' forward 50.

Pickett appeared rocked by the incident, swiping the man's hand away and was attended to by Richmond ground staff at three quarter time.

The incident sparked calls for a life ban from attending games for the spectator.

"You never ever, ever, ever touch a player on the ground – I don't care who you are," he said," Jordan Lewis said from the commentary box, via Fox Sports.

"That fan right there should be banned for life.

"I would hope that that fan was ejected straight away and the right process and protocol should be followed.

"It's a no-go zone – that should be worldwide in any sport."

A security guard went to the fan immediately after the contact was made.

Pickett had gone with Bontempelli through the third quarter, who kicked three goals during the term.

The AFL are due to assess the matter, according to reports.

Richmond coach Andrew McQualter weighed in on the incident post-match.

He said it's now in the hands of the league.

"I don't know full details, but it shouldn't happen," he said.

"We love fans in our game, and they're so critical to our game, but our players should never, ever be touched when they're on the football field.

"I think all Marlion was doing was alerting Tim (Livingstone) to the fact that something happened, and just getting security to deal with it and the AFL will deal with it now."

Pickett had twelve disposals and kicked a goal during the contest.

The Dogs ran out 19.12 (126) - 10.11 (71) victors after a nine-goal first quarter placing more roadblocks in front of Richmond's late run at a finals berth.