A Tasmanian horse who has beaten one of the leading South Australian Derby contenders has earned a Melbourne campaign.

Tasmanian Derby winner Jerilderie Letter's first Melbourne appearance could come as soon as Saturday at Caulfield, with the gelding nominated for a 1200m race against his own age.

But Tasmanian trainer Adam Trinder said on Monday that it was more likely he would wait until a Moonee Valley race on June 4 to launch the three-year-old's interstate preparation.

Jerilderie Letter won three consecutive stakes races in his home state during the summer, culminating in his narrow Tasmanian Derby win over the Darren Weir-trained Howard Be Thy Name in February.

Howard Be Thy Name has since won a Listed and Group Three race in South Australia and is on the fourth line of betting for Saturday's South Australian Derby ahead of acceptances on Tuesday.

Jerilderie Letter's six wins from seven starts has Trinder looking to test him in Melbourne during the winter.

"I just want to see where he lines up and he'll probably just have a two to three run campaign through the off-season in Melbourne and probably come back for the summer carnival (in Tasmania)," Trinder said.

The Moonee Valley race in three weeks, like Saturday's Caulfield option, is over 1200m for three-year-olds.

"He got out to a Derby journey but I don't think he's a genuine stayer," Trinder said.

"I think he's 1400 to 1600 metre type horse."

Jerilderie Letter was given a break after winning the Tasmanian Derby (2200m), having won the Listed Tasmanian Guineas and Listed Hobart Guineas in his two starts before that.

"He seems to be coming along good," Trinder said.

"He had six weeks off and didn't let right down, so he's come back to hand quite quickly."