A hit-out against older horses at Cranbourne on Tuesday has promising colt Crack A Roadie on target for his autumn missions including the Group One Blue Diamond Stakes.

Trainer Stephen Theodore, in New Zealand for the Karaka yearling sales, said reports from Cranbourne were that Crack A Roadie trialled in impressive fashion over 800m.

"I haven't seen the trial but I've spoken to my foreman and Craig Williams, and Craig said he felt fantastic," Theodore said.

"We organised a trial for him against older open horses to give him a bit more depth of competition and he won the trial in slick time."

Theodore said it was "all systems go" towards the $250,000 Inglis Premier (1200m) at Mornington on February 13.

"Then it's ten days into the Blue Diamond," the trainer said.

The Cranbourne trainer said he wanted Crack A Roadie to go up against older horses because Williams felt the youngster didn't get enough out of his jump-out against his own age last Monday.

Crack A Roadie was among the horses paid up for on Tuesday at the third declaration stage for the $1 million Blue Diamond Stakes (1200m).

The son of Charge Forward closed quickly to win on debut at Moonee Valley on Cox Plate day before running second in the Maribyrnong Plate at his next start.

Theodore has made no secret of his high opinion of the colt and said he had noticed a difference from the spring to now.

"He's a horse that's developed now and is very strong and athletic," he said.

"He's always had that brilliance which we seen in his first start, but now he's got a racing brain. He's a pretty faultless horse and a pleasure to be around."