Boss discards his Derby horse

Champion big race rider Glen Boss has jumped off Absolutelyawesome for the 150th running of the Group I AJC Australian Derby at Randwick on Saturday week.

Boss had the ride on the Mike Moroney-trained three-year-old, but a disappointing performance last Saturday in the Group I Rosehill Guineas has seen him locked in to ride the filly Shamrocker in the $1.5 million feature.

Boss rode Shamrocker to victory in the Group I Australian Guineas at Flemington four weeks back before she finished third behind Kiwi sensation Jimmy Choux in the Rosehill Guineas.

Boss said he holds Absolutelyawesome in high regard, but he doubts the horse is “mentally mature enough” to win a Derby.

Meanwhile, Corey Brown has secured the ride on Ajax Stakes winner Pureness from the Gai Waterhouse stable in the Group I Doncaster Mile on April 16.