Steve Smith is about do the unthinkable, joining forces with two New Zealanders as he searches for his next win in the sporting arena.

Having just clinched a Trans Tasman series victory against the Black Caps, Smith will momentarily put his summer of cricket rivalry to one side at Rosehill on Saturday.

As a racehorse owner, the Test captain will team up with two of New Zealand's best-known sporting exports, leading trainer Chris Waller and glamour jockey James McDonald.

Smith is a part-owner of Cauthen's Power, one of the favourites in the ATC Farewells Jimmy Cassidy Handicap on Saturday.

And despite a wide barrier, Waller rates the imported galloper the best of his four runners in a race named in honour of another kiwi jockey.

"Cauthen's Power might need a Jimmy Cassidy special from James McDonald," Waller said.

Cassidy has been a trailblazer for modern-day New Zealand jockeys in Australia and Waller says McDonald could easily be held in the same regard before his career is over.

"He is dead-seat world-class," Waller said. "He is what punters want, owners want and what trainers want.

"He's a credit to himself and to the people who have helped build him."

McDonald is Godolphin's No.1 rider in Australia, but he is also building a formidable relationship with Waller, winning the Group One Coolmore Stud Stakes and the Zipping Classic for the stable during the Melbourne spring carnival.

Cauthen's Power is one of four rides McDonald has for Waller at Rosehill with the five-year-old coming off a last-start midweek win at Warwick Farm.

"Even though he's drawn off the course I'd still be leaning towards him. He gets back anyway, but he still needs pace on."

McDonald will also ride Four Carat, Feast For Eyes and Dance Of Heroes for Waller.

Four Carat is an acceptor in a 3000m race at Moonee Valley on Friday but is expected to be switched to Sydney where he will run against two stablemates in the Kiwi Handicap.