Leading Sunshine Coast Guineas contender Skylimit will have to pass a veterinary examination to take his place in the Group Three race.
Trainer Gai Waterhouse told stewards the colt had shifted his off hind plate during trackwork on Thursday.
Queensland's chief steward Allan Reardon said Skylimit was examined on Friday morning and showed some signs of soreness in the leg.
He said he would be examined again on Saturday morning to determine his fitness.
A half brother to 2013 Golden Slipper winner Overreach, Skylimit finished second to Jumbo Prince in the Toowoomba Guineas two weeks ago.
Australian Oaks runner-up Winx is the steady favourite for the Guineas, her lead-up to the Queensland Oaks on May 30.