Trainer Tony McEvoy believes Azazel has taken improvement from his first-up race and remains right in the mix for the $1.5 million Blue Diamond Stakes.

Azazel gets the chance to press his Diamond claims in Saturday's Prelude for colts and geldings at Caulfield, two weeks before the Group One Blue Diamond.

"He's a very good colt and he's done nothing to tell me different," McEvoy said.

McEvoy has two of his Diamond hopes running on Saturday with Adelaide debut winner Roomooz running in the Fillies Prelude.

"She's a nice filly. I like her," McEvoy said.

"She did a good job in Adelaide. They ran pretty slick sectionals in that race then she trialled very nicely at Geelong.

"This will be the big test for her to see where she sits. I'll know a lot more after this weekend whether she's in the mix for the big race or not."

The Fillies Prelude has 16 nominations including Catchy, Limestone, and Godolphin's Gimcrack Stakes winner Jorda.

The male division also has 16 entries including Pariah, Property, and Cao Cao.

Azazel won at Moonee Valley on debut in October before finishing fourth in the Maribyrnong Plate.

He resumed in the colts and geldings Blue Diamond Preview on January 26 and after being outsprinted by winner Property early in the straight, he closed the race off for second, beaten 1-3/4 lengths which McEvoy described as a super first-up run.

"He just got a bit too far back in that race," he said.

"You would have thought he would have struggled to run a place on straightening but he ran second. It was a very good performance."

McEvoy said Azazel had trained on well.

"He's tightened up from it which is what he needed," he said.

"You can't have these babies at their top for their first run and expect them to be at their top at their third run.

"I want him peaking on the 25th of February."

McEvoy is looking to have Aspect, Azazel and Roomooz in the Blue Diamond if they perform at their next starts.

He said Aspect was a little disappointing in Saturday's Chairman's Stakes, finishing second last, but was "hot and bothered" on the day.

He said he would run next in the Talindert Stakes and if he performed well he would back up in the Diamond a week later.