Juvenile Construct is making all the right noises but Peter Snowden will reserve judgement on his Golden Slipper credentials until he sees the colt return on race day.

A $650,000 yearling purchase, Construct showed good natural talent to finish second to Shaquero at his only appearance in the Breeders' Plate.

Shaquero has franked the form by winning the Magic Millions Classic and Construct has likewise gone in the right direction since his October debut.

He has shaped well in two recent trials and has pleased the stable with his work at home but Snowden says the ultimate test will come when he resumes in Saturday's Canonbury Stakes (1100m) at Rosehill.

"Everything about him says that (he's a Slipper type) but they've got to do it race day, that's the litmus test," Snowden said.

"Trackwork and good sorts and breeding mean nothing when the gates open so he's got to bring it to the races on Saturday.

"If he does, he looks a likely type."

A son of super sire I Am Invincible, Construct was clinging to favouritism with TAB fixed odds on Thursday following strong early support for the Chris Waller-trained first starter Home Affairs.

Also by I Am Invincible, Home Affairs showed natural precocity to race away with a recent Rosehill barrier trial and after opening at $6 had firmed into $3.30.

Peter and Paul Snowden will also start Bullpen, who is raced in similar interests to Construct and finished second in his most recent trial.

"He's a typical Deep Field. He's got good gate speed and he'll be allowed to use that on Saturday and just see where it takes him," Snowden said.

Bullpen is a $34 chance for the Canonbury Stakes and Snowden agrees the market has got it right, favouring Construct as the stable's leading chance.

"He's the more professional and the one who has shown us the most," he said.

"He has already been exposed to a good level and performed so he'd be the pick of the two."

Jason Collett will partner Construct with Tim Clark booked for Bullpen.