Chris Waller may yet salvage something from Zoustar's international excursion, cut short on Wednesday because of a career-ending injury.

The valuable colt suffered a slight strain to a suspensory ligament while preparing for next month's Diamond Jubilee Stakes at England's Royal Ascot carnival.

Given he will stand at Widden Stud this breeding season, Waller and the colt's owners have confirmed Zoustar will not race again even though his injury is not serious.

But the leading Sydney trainer is clearly shattered to have planned and executed Zoustar's trip to the minute, only for bad luck to strike.

"To go all that way with the one horse, it's a real kick in the backside," Waller said.

"I got the feeling we were representing Australia. We had built ourselves up, we thought we had the right horse and he set off on a mammoth trip, everything just seemed to be coming together so well.

"To have that one horse to take that big step on the big stage and then for it to go wrong is just shattering."

The leading Sydney trainer has been left with three return flights to England having planned to travel there twice before the horse raced and again for the Diamond Jubilee.

On Wednesday, the disappointment of Zoustar's injury was too raw for Waller to decide whether he would attend Royal Ascot as a spectator.

But his curiosity might just sway him to head to England.

Waller wants to train a Royal Ascot runner some day, and a first-hand assessment of Zoustar could provide valuable information for the future.

"If I go, I will go and see him before he comes home and see how he is in the week of Ascot because I reckon we nailed it in terms of timing," Waller said.

Zoustar retires a dual Group One winner with earnings of more than $1.4 million from nine starts and will stand for a service fee of $44,000.