MIAMI - Argentine sensation Lady Sprinter created a bit of a stir when she showed up at Santa Anita last fall to take on the best filly and mare sprinters in this country in the Breeders' Cup Filly and Mare Sprint. Lady Sprinter came to the U.S. having won eight of her first nine starts, including a couple of Group 1 races in Argentina. She then raised a few eyebrows when working a blistering five furlongs in 45.32 seconds between races at Santa Anita early Breeders' Cup week. But in the end Lady Sprinter proved no match for her competition in the Filly-Mare Sprint, finishing ninth behind Ventura after failing to show her brilliant speed. Trainer Juan Reviriego gave Lady Sprinter one more chance at Santa Anita, but after another disappointing performance in the Kalookan Queen Handicap, he packed his bags and his filly and headed east. Reviriego found a new home in south Florida, settling in this winter at Gulfstream Park before moving his small stable across town to Calder, where Lady Sprinter will make her 2009 debut in Sunday's $34,000 co-feature. Lady Sprinter, whose only setback in nine races in Argentina came about after she lost her action in her only start on grass, has been working extremely well for her return. Most recently she posted a bullet five-furlong work in 1:01.60 here on May 14. Lady Sprinter will face only five rivals in her south Florida debut, the most dangerous of whom figure to be Orinoquia and trainer Marty Wolfson's uncoupled pair of Jessica Is Back and Seaside Affair. Orinoquia remains winless since capturing the Leave Me Alone Stakes here nearly a year ago, the second of back-to-back stakes she won for the Caroni Stable and trainer Rodolfo Garcia last spring. Orinoquia has not started since finishing second under allowance conditions at Tampa Bay Downs on April 21. Jessica Is Back was sent back to Calder after being haltered for $50,000 out of an optional claiming race at Aqueduct on April 23. The daughter of Put It Back began her career in south Florida with trainer Tim Ritvo, who sent her out for her first four victories, including a couple of allowance tallies over the local strip in November 2007. Grade 2 winner in allowance Perhaps an even more intriguing matchup will take place a bit earlier on Sunday's program when Grade 2 winner How's Your Halo takes on the exciting Americanrevolution going 6 1/2 furlongs under allowance conditions. How's Your Halo upset Ikigai to capture the Grade 2 Richter Scale this winter at Gulfstream Park and was also second here last summer behind Benny the Bull in the Smile Sprint. Americanrevolution has shown stakes-caliber performances on several occasions during a puzzling career that has also seen him beaten off more than a dozen lengths under a $20,000 claiming tag in 2007. Americanrevolution has returned once again to trainer Bill White's barn and will try to keep his record perfect over the local strip, where he's undefeated in three starts. He won an optional claiming race here on May 2 and received a 102 Beyer Speed Figure. Change in training schedule Construction begins next week on the new Calder slots parlor, and along with it comes a revised training schedule. Beginning Tuesday, the main track will be open for training from 5-8:30 a.m. with no break, with the starting gate available from 7-8:30 a.m. The training track will be remain open from 5-10 a.m. daily. * Cassidy's Pride worked four furlongs in 48.62 seconds and galloped out five-eighths in 1:01.80 while equipped with blinkers over a sloppy track on Friday. Cassidy's Pride was beaten less than a length when third in the Snurb Stakes on May 2.