Fremantle key defender Alex Silvagni will miss the Dockers’ opening-round clash of the 2013 AFL season after pleading guilty to head-butting Adelaide forward Jared Petrenko.

Silvagni risked being banned for two weeks had he taken the case to the tribunal.

North Melbourne star Brent Harvey will front the AFL Appeals Board on Tuesday night to contest a two-match ban for striking West Coast defender Adam Selwood.

Harvey has already been suspended for the Kangaroos’ first four games of 2013 for a separate striking incident involving Eagles midfielder Daniel Kerr.

If the charge involving Selwood is also upheld, Harvey’s total ban will be six games.