Gary Portelli has experimented with a change of riding tactics on Spaceboy at the barrier trials and believes he might have found the key to unlocking the youngster's abundant potential.

The colt has shown natural speed at his three race starts, which have included minor placings behind one-time Golden Slipper favourite Tassort and Unite And Conquer and Exhilarates in the Wyong 2YO Magic Millions.

But compared to what the son of Deep Field has shown on the training track, his form has not been quite as good as his trainer has expected.

After the juvenile resumed with a second to Splintex over 1000 metres on the Kensington track earlier this month, Portelli decided to take him back to the trials and see how he responded to a more quiet ride.

The initiative was a success and the new tactics will be implemented when Spaceboy heads to Rosehill on Saturday.

"He ran second first-up over 1000 on the Kensington track and he ran a real good race but just couldn't quite reel in the winner," Portelli said.

"Since then he's trialled and we rode him back off the pace and he flew home from last.

"I'm not saying we'll drop him out to last at Rosehill, but we'll certainly be riding him conservatively and seeing if he can hit the line stronger.

"If he reproduces his track work he's a Group One horse."

Portelli is almost certain to resist the temptation of a Brisbane winter carnival trip for Spaceboy and is leaning to giving him his chance at Rosehill before tipping him out for the spring.

While Spaceboy is rested, stablemate Dio D'Oro is set to be a mainstay of the trainer's team this winter.

The colt put together a three-race winning streak on rain-affected tracks during the off-season last year before being outclassed in some of the early-spring three-year-old features.

He was nominated for the Randwick meeting on Saturday but Portelli opted to keep him home for another week in the hope of a break in Sydney's dry autumn weather.

"He's predominantly a wet tracker so we got him back in for the winter but unfortunately these wet tracks aren't around," Portelli said.

"We're hoping by waiting an extra week the rain might come. His form is enormous on heavy tracks.

"We'll be watching all the tracks in Australia and wherever it rains he'll be on a float heading that way."