Unbeaten Marble Nine is set to make his city debut after victories at Mornington and Moe.

Sometimes finding the right metropolitan race for a horse is nearly impossible as trainers Leon and Troy Corstens can vouch for. 

Ideally an 1100m race around a corner was the Corstens father-and-son training operation preferred option for Marble Nine who will make his city debut at Flemington on Saturday. 

Marble Nine was entered for a 1200m race at Caulfield last Saturday, but Troy Corstens said the stable elected to wait until Saturday for the 1100m ATA Trainers's Trust Handicap. 

"I really would have liked the 1100 metres at Caulfield," Corstens said. 

"He would have got the 1100 (metres) around a bend and I would have been happy, but it would have been 1200 metres around a bend at Caulfield or 1100 metres down the straight at Flemington. 

"So, we've elected for the 1100 metres down the straight." 

Marble Nine has raced on only two occasions, registering a maiden win over Our Cracklin' Rosie at Mornington last November before a break. 

He resumed to win at Moe over 1000m, racing on the speed in recording a 2-3/4 length win in a benchmark 64 grade race on May 24. 

On Saturday, Marble Nine tackles open three-year-old company where he opposed to Steel City, a Group 3 winner, and horses of the calibre of Namesake, Pivot City and last start winner Title Fighter. 

Corstens concedes Saturday's contest will not be easy, but the gelding gets into the race with 52kg after the claim for apprentice Tatum Bull. 

The rail on Saturday will be out eight metres and if the last Flemington meeting is any indication, the outside of the straight may again be the place to be. 

Marble Nine has drawn gate 16, coming into barrier 13 if the four emergencies do not gain a start. 

"He's a really nice horse, and whether he will handle the straight, I'm not sure," Corstens said. 

"I do think he's really effective around a corner, so we'll find out."