ADELAIDE small forward Shane McAdam will serve a three-match suspension after failing to have his ban for a high bump on Greater Western Sydney's Jacob Wehr overturned.

In a marathon hearing at the AFL Tribunal Appeals Board on Thursday night, Adelaide's legal team argued McAdam's sanction, handed down by the Tribunal on Tuesday night, was an "error in law" with a grading that was "manifestly excessive".

They contended the grading of 'severe' impact should have been downgraded to 'low' and too much weight was assigned to the potential to cause injury.

However, the Appeals Board disagreed, saying the penalty for the brutal hit would stand.

After 75 minutes of evidence and 90 minutes of deliberation, chair Max Kellam handed down the verdict.

"In our view the Tribunal committed no error of law in concluding that the classification of impact was severe," Kellam said.

BLOG RECAP All the action from McAdam's appeal, R2 teams

"The potential for injury is clearly a significant matter … the first principle in the listed guidelines is to prioritise the health and safety of players.

"There is no limitation on how much weight should be placed on any of the relevant considerations. It was open to the Tribunal to place great weight (on potential for injury) in our view."

McAdam's counsel Tom Duggan KC was fighting the 'severe' impact grading, saying that potential to cause injury was just one of four elements that should be considered when grading impact. 

He said the evidence at the Tribunal of biomechanics expert Dr Robert Crowther, that showed the impact of the bump was to the upper chest, was dismissed.

"We say the effect of that was to reimagine the incident in a way that was impermissible," Duggan said.

"It's an error of law because all you were doing was looking at one matter of four, as if it was the determinant factor … and you've applied that to take it from 'low' to 'severe' (impact).

"This was a bump to the chest and the arm and all of a sudden it's being charged as a head incident … and being elevated to something that it's not.

"You're changing the character of the incident.

"Something has gone terribly wrong in this case, and this has been wrongly categorised."

McAdam will miss matches against Richmond, Port Adelaide and Fremantle.

His suspension follows two other bans during round one, where Melbourne's Kysaiah Pickett and Sydney superstar Lance Franklin were also suspended for bumps.