UNDER-SIEGE Eagle Andrew Gaff has touched down in Melbourne ahead of Tuesday night's AFL Tribunal, where he's set to find out his penalty for his crude off-the-ball punch on Fremantle's Andy Brayshaw.

The hearing has been set for 5pm AEST, with Greater Western Sydney's Jacob Hopper to challenge his umpire contact charge afterwards.

Gaff left Perth on a 6am flight on Tuesday, accompanied by West Coast's integrity services manager Peter Staples.

He landed in Melbourne just after 11am, where he was immediately whisked away by security in a car on the tarmac.

Eagles CEO Trevor Nisbett has also been seen at AFL House in Melbourne.

It's unusual for a player based outside Victoria to travel for a tribunal hearing, with such matters usually dealt with by video link. 

However, the nature of Gaff's case and the expectation he'll receive a lengthy suspension are exceptional circumstances that mean there's no reason he can't face the music in person.

ANALYSIS Tribunal could end Gaff's season

Gaff is also a Victorian, and would have the support of his family while in Melbourne.

There have been calls for the 26-year-old to receive a ban of anywhere between six and 12 weeks for his damaging punch in Sunday's derby at Optus Stadium.

Brayshaw won't play again this year after the horrendous incident in which he suffered a broken jaw, displaced teeth and dramatically split lip.

The Eagles are expected to argue Gaff was trying to make contact with Brayshaw's chest and not his head.

West Coast coach Adam Simpson said on Monday Gaff was devastated and "really disappointed in himself" after the "grossly out of character" incident.

All other sanctions that stemmed from round 20 have been accepted.