The South Australian Derby came around too quickly for Happy As Hell but the gelding will be on trial for another Classic when he runs at Caulfield on Saturday.

Happy As Hell chases back-to-back wins at the track in the L U Simon Builders Handicap (2000m) which could be a stepping stone to the Group One Queensland Derby next month.

"If he went really well tomorrow we would definitely give it a fair bit of thought then, that's for sure," co-trainer Terry O'Sullivan said.

"We're hopeful he will. He's taken a pretty steep weight rise but hopefully he can handle it."

O'Sullivan had initially considered aiming Happy As Hell at the South Australian Derby (2500m), which is run on Saturday, but a couple of issues before the gelding resumed in March from a summer break set him back.

"He actually got a spider bite and that really set him back," O'Sullivan said.

"He was treated pretty heavily for a few days after that so it was a bit nasty.

"Then he was supposed to have a trial at Terang and he got a little bit of a virus so we had another little setback there."

Happy As Hell made his return in the Listed Bendigo Guineas in mid-March and was unplaced in his first two starts of the campaign over 1400m before stepping to 1800m at Caulfield and winning two weeks ago.

He carried 56kg, notching his second win from three starts at the track, but rises 4kg on Saturday.

"We think he's probably improved a little bit," O'Sullivan said.

Happy As Hell is on the second line of betting at $7 behind Synthetic ($3) and they are among seven horses in the race nominated for the Queensland Derby, including the Peter Moody-trained filly Lady Tatia.

Dwayne Dunn won on Happy As Hell last start and retains the ride.

"I thought he would be riding in Adelaide tomorrow but we were pretty pleased he was riding at Caulfield," O'Sullivan said.