Top jockey Peter Knuckey will miss Super Saturday at Ascot with a compound fracture of his T7 vertebrae to sideline him for up to 10 weeks.
Knuckey suffered the injury in a fall at trackwork last Thursday.
He was aiming to return to riding this week but scans confirmed a fracture.
“He’s looking at eight to 10 weeks at this stage,” Knuckey’s racing manager Kyle Nowland said.
Knuckey, who sits second to Paul Harvey in the jockeys’ premiership with 18 city wins, was booked to ride Power Princess in the Group 1 Crown Perth Winterbottom Stakes on Saturday week.