A slick jump-out at Flemington has Tony McEvoy confident Concealer is back on track for the Blue Diamond Stakes.

A debut winner during Melbourne Cup week at Flemington last November, Concealer is set to tackle the fillies division of the Blue Diamond Preludes at Caulfield on Saturday.

Concealer bettered 47 seconds for the 800m jump-out on Friday morning under Mark Zahra, a pleasing turnaround from a messed-up gallop at Moonee Valley a few days earlier.

McEvoy said Hey Doc and Concealer were forced to work together at the Valley after two others pulled out which was not his plan.

"She's had a faultless preparation apart from a gallop at Moonee Valley last Monday which was my fault," McEvoy said.

"She rectified that in the jump-out and Mark gave me a very nice report after it.

"He said she needed it, which I knew she would, as I had factored that in and it should clean her up nicely.

"The Prelude will bring her right to where we need her for the major."

McEvoy holds some concerns Concealer may not handle the Caulfield circuit.

He said he would be more confident if she was racing down the straight at Flemington.

"She's got such an expressive action," he said.

"If she can cruise around the bend and if Mark can have the luxury of not putting her under pressure until they straighten I think she will be fine."

McEvoy said he planned for the filly to have only the one run leading into the Blue Diamond on February 27 with a trip to Sydney to follow, despite her not being a Golden Slipper nomination.

"She'll have to win her way in Slipper," McEvoy said.

"If she won a Blue Diamond, that would make it a lot easier and we'd probably pay up for her."