Spieth has been all but ruled out of Saturday’s Gr.1 Kingsford-Smith Cup (1350m) at Doomben.

The New Zealand-bred son of Thorn Park has suffered a foot injury, with the Gr.1 Stradbroke Handicap (1350m) now a more realistic chance of him boosting his stallion profile.

“He was going really well and he just shifted a shoe last Thursday morning and pricked his foot, so we are just monitoring him at the moment,” co-trainer Ben Hayes said.

“At this stage he is unlikely to run. He's not 100 per cent sound at the moment and he'll need to improve if he is going to run in that race.

“If not, he'll just continue on and we'll run him for the Stradbroke, he'll be a good chance in that race.”