The Gai Waterhouse & Adrian Bott-trained Alligator Blood is under an injury cloud heading into the Group 1 Cox Plate (2040m) on Saturday at Moonee Valley.
The Underwood Stakes winner from earlier in the spring presented lame in the near fore when inspected by Racing Victoria (RV) veterinarians on Thursday morning.
The stable has informed Racing Victoria stewards that the horse has displayed no recent lameness, has not been treated for lameness, and has missed no work.
Stewards confirmed the horse was lame and would be looked at again on Friday afternoon in order to gain clearance to compete in the AUD $5 million feature.
Alligator Blood didn't appear at Moonee Valley for Breakfast With The Best on Tuesday morning prior to the Cox Plate barrier draw, with the Waterhouse & Bott stable opting to work him on the Flemington course proper instead.
It is protocol for RV vets to inspect all horses accepted into the key races during the Melbourne Spring Carnival, and they were able to look at 10 of the 12 Cox Plate runners on Thursday morning.
Young Werther from the Danny O'Brien yard is to be inspected on Thursday afternoon and the Chris Waller-trained El Bodegon will be examined on Friday morning.
All other horses have been passed fit to race.