Ben Melham is on standby to ride Puissance De Lune in Saturday's Cox Plate should Glen Boss fail in his appeal against a suspension on Tuesday.
Puissance De Lune's owner Gerry Ryan confirmed Melham would ride the grey if Boss couldn't.
Melham rode Puissance De Lune in trackwork on Tuesday morning at Warrnambool.
Boss faces the Racing Appeals and Disciplinary Board in Melbourne on Tuesday afternoon to appeal the severity of a 12-meeting suspension incurred in last Saturday's Caulfield Cup.
Melham rode Black Caviar to the mare's first Group One win when he picked up the ride after her jockey Luke Nolen was suspended.