Melbourne jockeys' premiership contender Damien Oliver will not be riding at Ballarat on Wednesday due to illness.

Oliver is two wins behind leader Craig Williams in the Melbourne premiership and one win behind Dwayne Dunn but relinquished his rides at the midweek metropolitan meeting on Wednesday morning.

His manager Mark Van Triet said the jockey was hoping to ride on Thursday and said he will be right for Caulfield on Saturday.

"He's been fighting a bug for the last couple of days and he thought he was coming good but he had a rough night last night, so to get himself right for the weekend he felt it was best to sit out today," Van Triet said.

"He just wasn't fit enough to ride today. Hopefully he can ride tomorrow, he wants to ride tomorrow."

Williams is also not riding at Wednesday's metropolitan meeting because he is serving a careless riding suspension incurred last Saturday.

Dunn has picked up the ride on first starter Charlie Garcon from Oliver in Wednesday's opening race.

Charlie Garcon is one of six rides for Dunn.

Dunn's other rides on the card include Longeron in the heat of the Winter Championship Series.