John Nisbet is resigned to losing one of his stable's best assets but at least he's got a horse in winning form to help soften the blow.

Nisbet is about to sign over the riding papers of his daughter Kayla, conceding her form in Victoria during a stint with David Hayes has made a compelling case for a permanent move.

"Kayla's days with me are over at the moment," he said. "She is getting some great opportunities and her confidence is up."

Kayla will be at Moonee Valley on Saturday where she has five rides, the best of which appears to be Spacecraft for her new boss.

As the 18-year-old settles into life as an apprentice at Lindsay Park, her father will be trying to make the most of a rare foray into Sydney racing at Rosehill on Saturday.

He will saddle up Diamondsinthenight, once a member of the Anthony Cummings' Randwick team, for a city return in the Significant Stakes, a middle-distance test for two and three-year-olds.

Diamondsinthenight was ridden from the front to win the latest of his past two victories on Canberra's synthetic track, confirming a decision to switch riding tactics had been the right one.

"He was losing interest and then running on at the end when it was all over," Nisbet said.

"Since we have stepped him up in distance and been a bit more positive on him he's reacted well."

Diamondsinthenight is one of the outsiders in the 1900m race but his pedigree says he will make a stayer and there is a form reference from a recent Wagga Wagga placing to give Nisbet some confidence about his Rosehill prospects.

At his first outing for Nisbet, Diamondsinthenight finished second to Belle De Coeur, a filly who then ran up to her promise with an exciting last-to-first win in much better company at Rosehill.

But Nisbet is reserving judgment on a similar progression for Diamondsinthenight.

"It's a tricky assignment and you've got to have a fair bit in your favour going to Sydney but hopefully he'll do something," Nisbet said.