Training partners Trent Busuttin and Natalie Young are hoping it's third time lucky for Main Stage in the South Australian Derby.

The three-year-old has already finished fifth in two Derbys this season, the Victoria Derby at Flemington and the Australian Derby at Randwick.

After a five-week break, Main Stage runs in Saturday's Group One race at Morphettville.

"We've chased two Derbys, so why not go for a third," Young said.

"I know it's a big ask going five weeks between runs and going 2500 metres, but we trialled him at Cranbourne over 1400 metres.

"It was only his fourth run in the Australian Derby so this is only his fifth run.

"If it was his sixth run in Sydney then he probably would have gone to the paddock but he's trained on, he's eaten everything, he looks great so you've got to give it one more go."

Main Stage will be ridden for the first time by Damien Oliver who is chasing his 111th Group One winner.

Oliver went to Cranbourne recently to have a sit on the gelding in a jump-out.

Young said the hit-out was perfect before a gallop on Tuesday morning which she said was super.

"He's trained on well since the Australian Derby and I think he'll run a good race," Young said.

Main Stage has met with steady support, firming from $12 to $8.50, the fourth line of betting.

The Darren Weir-trained Leicester is the $4 favourite ahead of Tangled ($6) and High 'N' Dry ($6.50).

Main Stage's stablemate Johnny Vinko ($26) is third emergency for Saturday's race and has made the trip to Adelaide.

Johnny Vinko is one rung closer to gaining a start with Darren Weir indicating Amerock won't be taking his place.

"It's unlikely that he'll get a start but the owner was happy to put him on the float, send him over, and if there's three scratchings, he gets a run," Young said.

"You'd be disappointed Saturday morning if that happened and you weren't there."