ARCADIA, Calif. - The undefeated 4-year-old Flightline worked five furlongs in 1:01.20 at Santa Anita on Sunday, continuing preparation for his first start since late December in the Grade 1 Metropolitan Mile Handicap at Belmont Park on June 11. Flightline was exercised by trainer John Sadler’s assistant, the former jockey Juan Leyva. The workout was the fourth for Flightline, and first at five furlongs, since he returned to serious training following a brief rest in late winter when he was diagnosed with a strained hock. “We’re working with him to try to get him to relax,” Sadler said. “We’re right on track for what we’re doing.” A three-time winner, Flightline has not raced since a win by 11 1/2 lengths in his stakes debut in the Grade 1 Malibu Stakes for 3-year-olds at seven furlongs on Dec. 26. :: Win big at Santa Anita: Get DRF Past Performances, Picks, Clocker Reports and Betting Strategies.