CARLTON midfielder Zac Williams' ban has been upheld by the AFL Tribunal. 

The rough conduct charge occurred in the first quarter of the Blues' AAMI Community Series game against St Kilda last Thursday night.

The MRO has graded the incident as careless, medium impact and high contact, resulting in a one-game suspension.

The decision was upheld at the AFL Tribunal on Tuesday night, meaning Williams will miss Carlton's Round 1 season opener against Richmond.