Leading Irish trainer Aidan O’Brien will make his first visit to Australia in six years, with lightly raced colt Adelaide to start in the Cox Plate.

Coolmore racing manager James Bester said O’Brien would bring Adelaide to the $3 million Cox Plate after the European three-year-old contests Sunday’s Secretariat Stakes (2000m) at Arlington Park, Chicago.

A 50-percent stake in the son of Galileo had been sold to clients of Chris Waller.

“Should the horse remain in Australia after the Cox Plate then that’s where he would go,” Bester said. “Whether he remains in Australia after the Cox Plate is the question.”

Bester said Coolmore believed Adelaide, a runner-up in the Belmont Invitational Derby at Belmont Park early last month, was a “genuine Cox Plate contender”.

“We are hoping he runs well in America next week, we’re hoping that justifies a trip to the Cox Plate and then depending on what unfolds there’s a possibility he may remain in Australia,” Bester said.

Adelaide is one of five horses — Kingfisher, Magician, Table Rock and Venus de Milo are the others — O’Brien nominated for the Cox Plate.

Bester described Adelaide as “the most likely” of the quintet to make the journey to Melbourne.

“They haven’t been entered for fun, they’re all possibilities,” Bester said.

Adelaide also boasts a second behind Eagle Top in the King Edward VII Stakes at Royal Ascot in June.

O’Brien has not returned to Melbourne since 2008, when his three runners — Septimus, Alessandro Volta and Honolulu — finished 18th, 20th and 21st in the Melbourne Cup  behind Viewed.

Racing Victoria stewards, chaired by Terry Bailey quizzed O’Brien over the tactics given to his jockeys in the Cup — a narrative that O’Brien did not appreciate.