SHANE Mumford has had his one-match ban for striking overturned at the AFL Tribunal on Wednesday night, making him eligible to return for Greater Western Sydney in round three.

Mumford successfully argued his strike on Sydney midfielder George Hewett had not been intentional, with the Tribunal ruling his action was careless, a finding that downgraded his penalty to a $3000 fine.

Mumford was suspended for one game by Match Review Officer Michael Christian after catching Hewett with an open hand to the head during a practice match last Friday.

The Tribunal jury Richard Loveridge, Jason Johnson and Michael Jamison agreed with the MRO's finding that Mumford had struck Hewett with low impact, but after just 10 minutes of deliberation overturned the intentional grading.

"Obviously I was extremely flat knowing that I was going to miss the third round, not being able to play until the fourth round was pretty devastating, so to get the result we did tonight was good," a relieved Mumford said after the hearing.

WHO MAKES FINALS? Do the 2019 Ladder Predictor

Mumford still has to serve a club-imposed two-match suspension for the infamous white powder video that surfaced late last year.

Mumford challenged his suspension on two separate grounds: his action had not been intentional; and it was of insufficient impact to constitute a classifiable offence.

Mumford told the Tribunal he had been in a position to win the ball during last Friday's practice game when Hewett grabbed him around the neck and dragged his head down.

At that point, Mumford said he pushed Hewett with an open hand to try to break the Swan's hold on him, using just enough force to get Hewett off him so he could stay in the contest.

Nicholas Pane QC appeared as the AFL's legal counsel and argued Mumford's action was a forceful upward motion towards Hewett's neck and head that made contact with the Swan inevitable.

Mumford denied contact with Hewett's head had been inevitable, saying he hadn't known where Hewett's head was at the time given the Swan had dragged his head down.

Hewett gave evidence by phone and described Mumford's action as "a bit more than a push but impact was minimal".

The Swans midfielder agreed Mumford had brushed the side of his face with an open hand, but denied he tried to accentuate the force of the impact as he fell to the ground.

Officiating field umpire Leigh Fisher also gave evidence by phone and described Mumford's action as a push that hadn't warranted a striking charge, while also conceding a free kick should have been paid against Hewett for grabbing Mumford around the neck.

Mumford is still eligible to play in the JLT Community Series, and said after Wednesday night's hearing he was hopeful of taking some part in the pre-season competition.

JLT FULL FIXTURE Whereyour team's playing its warm-up games

GWS plays Essendon and West Coast in the first two rounds.

Mumford was making his return to football last Friday after a year out of the game, following his retirement at the end of the 2017 season because of ongoing foot injuries.

He played just the second half of the scratch match, but GWS coach Leon Cameron was "rapt" with his performance.

Mumford returned to the club last December as a rookie following Rory Lobb's move to Fremantle in the NAB AFL Trade Period.