John Shirreffs, who won last year's Kentucky Derby (gr. I) with Giacomo, has replaced Eoin Harty as trainer of last year's Norfolk Stakes (gr. II) runner-up A.P. Warrior.The son of A.P. Indy, owned by Stan Fulton, easily defeated Bob and John in an allowance race at Santa Anita following his fast-closing second to Brother Derek in the Norfolk. In his last two starts, however, he's finished fourth in both the Hollywood Futurity (gr. I) and El Camino Real Derby (gr. III)."After his last race, I wasn't that shocked at the news," Harty said. "(Fulton) said he just felt the decision was in the best interests of the horse."Shirreffs, who was given the news Wednesday, said A.P. Warrior is expected to arrive at his barn today, and that no plans have been discussed.A.P. Warrior had become rank fighting his rider in his last two starts and Harty had decided to try blinkers for the March 4 Santa Catalina Stakes (gr. II) after the colt worked well in them. Harty still has two promising 3-year-olds -- Barbican, who was withdrawn from Monday's Southwest Stakes with a throat ulcer, but is "90% better today," according to the trainer, and Barcola, who was fourth in an allowance race last time out.Shirreffs also has another talented 3-year-old in Jerry and Ann Moss' Tatsuji, who missed a few days training with an illness following his impressive maiden victory Dec. 29, but is now back working.A.P. Warrior was purchased at the Keeneland September yearling sale for $1.3 million. He's won two of his six starts, including a four-length maiden victory in his career debut at Hollywood Park.