Wertheimer Farm's Halfbridled, last year's champion 2-year-old filly, worked seven furlongs in 1:24 4/5 at Santa Anita Thursday in preparation for her 3-year-old debut in the $300,000 Santa Anita Oaks (gr. I) March 13.The daughter of Unbridled, who is unbeaten and untested in four starts, including a rousing victory in the Breeders' Cup Juvenile Fillies (gr. I), was scheduled to debut in the Las Virgenes Stakes (gr. I) last weekend, but a cough put her behind in her training and trainer Dick Mandella decided to wait for the 1 1/16-mile Oaks."She's really come along and blossomed out," Mandella said. "We'll train her up to the Oaks and then point for the Ashland Stakes (gr. I) at Keeneland. If all goes well and we feel she's run out of filly competition by the time we get to Churchill Downs, we'll think about the Derby. I'd love to have that dilemma. But we've got two races first."Halfbridled will not be lacking for competition in the Santa Anita Oaks, as she will take on the undefeated A. P. Adventure, winner of the Las Virgenes and Santa Ysabel Stakes (gr. III) for trainer Wally Dollase. Other Las Virgenes starters expected to run back in the Oaks are runner-up Hollywood Story; winner of the Hollywood Starlet (gr. I); the Bob Baffert-trained Friendly Michelle (third); and the Wayne Lukas-trained Stellar Jayne (fourth).In addition to the Breeders' Cup Juvenile Fillies, Halfbridled has won the Oak Leaf Stakes (gr. II) and Del Mar Debutante (gr. I).Also on Thursday's work tab, Mandella sent out Breeders' Cup Juvenile (gr. I) runner-up Minister Eric for a six-furlong spin in 1:12 2/5. The son of Old Trieste is scheduled to make his 3-year-old debut in the 6 1/2-furlong Baldwin Stakes on the turf.Santa Catalina (gr. II) winner St Averil worked six furlongs in 1:12 1/5 for the San Felipe (gr. II) on March 14.