LOUISVILLE, Ky. – Led by a trio of prospects from Kentucky Derby-winning trainers Brad Cox and Todd Pletcher, a total of 11 horses with designs on the Derby one week hence worked at Churchill Downs on Saturday morning. They were part of a frenetic day of activity that included a drill at Keeneland for another Derby-winning trainer, a postponed work at Gulfstream, and works at both Belmont Park and Monmouth for horses who likely won’t end up running.