Jockey Jordan Childs is keen to see lightly raced Convict Sam take another step up at Caulfield in the Galilee Series Final, with a view to a possible South Australian Derby tilt.

Childs rides the Archie Alexander-trained Convict Sam in Saturday's Listed race for three-year-olds over 2425m having been aboard the gelding in three of his four starts including a maiden victory over 2000m at Donald at his most recent appearance.

Convict Sam's sire is Melbourne Cup winner Fiorente and Childs liked the way the three-year-old worked through the line in his 2-3/4-length victory in the Donald maiden after taking a while to wind up and hit top gear.

"I think he's definitely going to run out the trip," Childs said.

"His win the other day was really good.

"He's a very casual sort of horse and with the blinkers on it sort of sharpened him up last time.

"Obviously he has got to go up in class and it's going to be a step up for him, but I think he should run well.

"I think the main aim for him is to go to the Derby over in Adelaide if he is good enough, but you've got to take one step at a time."

The Group One South Australian Derby (2500m) is at Morphettville on May 11.

Convict Sam was on the second line of early betting at $4.60 for the Galilee Series Final on Wednesday, with last-start Bendigo winner Secret Blaze the $2.90 favourite.

Trainer Tony McEvoy has the SA Derby as a target for Secret Blaze after Saturday.

Childs' book of Caulfield rides also includes Convict Sam's stablemate Saccharo who is the early favourite in a 1440m handicap for three-year-olds after his last-start third in the Listed Bendigo Guineas.

Childs expects the addition of blinkers to be a positive for Saccharo.

"He's going well," Childs said.

"With the blinkers going on I expect him to sharpen up a lot.

"He's probably looking for a mile but with the blinkers on over 1440 I expect him to be running very well."