Trainer Mark Newnham says a stable full of promising young horses will be the key to replacing Shadow Hero after the three-year-old's sale to Hong Kong.

Mark Newnham predicts dual Group One winner Shadow Hero to be a smash hit in Hong Kong as he looks toward the next generation of horses to carry his stable into the future.

The sale of the Randwick Guineas winner to Hong Kong interests was confirmed last week in a deal worth more than $3 million.

Newnham said it was never about money for Shadow Hero's former owners, also based in Hong Kong, but rather a transaction borne out of the travel restrictions and uncertainty caused by the coronavirus.

"It didn't really come down to money because there have been big offers for him all the way through from this time last year," Newnham said.

"But the owners aren't able to travel out here and watch him now. They weren't able to come for the last two runs this prep and wouldn't be able to come out here for the spring.

"There was a lot of factors in it and not really based upon money.

"It's sad to see him go because I still think the best is ahead of him but he's the right type of horse to do well there."

Shadow Hero has been purchased to contest Hong Kong's rich race series for four-year-olds which culminates in the Derby.

As Newnham's stable star, he will be difficult to replace, but the trainer is optimistic he can continue to build on his success of the past two seasons

"We've got a good group of young horses so something there will put its hand up," Newnham said.

"We're getting quite a few yearlings through the stable at the moment.

"They're all having their two-week look around, they get into the routine and then go back out."

Of his more established brigade, Splintex shapes as a horse who could spearhead Newnham's spring.

The winner of the Group Two Arrowfield 3YO Stakes during the autumn, a race claimed by Everest hopeful Classique Legend last year, Splintex has won five of his nine starts and continues to improve.

Quackerjack has also risen through the ranks to capture the Villiers Stakes and Liverpool City Cup at his most recent preparations, while filly Quintessa shows staying promise, placing behind Colette in the ATC Australian Oaks and Adrian Knox Stakes.