Chaparral tests Derby credentials Racing Post Trophy winner High Chaparral will have six rivals when he makes his seasonal debut in the Ballysax 3YO Stakes at Leopardstown on Sunday.Trainer Aidan O`Brien has also declared Twentytwoandchange for the Listed race over 10 furlongs to ensure a good pace for the son of Sadler`s Wells.The ?52,000 feature was won 12 months ago by the O`Brien-trained Galileo, who went on to glory in the Vodafone Derby.High Chaparral, a best-priced 16-1 chance for the Epsom Classic, will be ridden by stable jockey Michael Kinane.John Oxx is double-handed in Sunday`s race with the unbeaten pair Chartres and Tarifana, who both made winning debuts at the Curragh three weeks ago, while Dermot Weld runs Rahn.The line-up is completed by Smuggler`s Song, trained by Charles O`Brien, and Jim Bolger`s Alluring Park.O`Brien is also double-handed in both the 2000 and 1000 Guineas Trials on the card.Century City (Kinane) and Stonemason represent the Ballydoyle trainer in theLeopardstown 2000 Guineas 3YO Trial over a mile, while he runs Lahinch (Kinane) and Pietra Dura in the Leopardstown 1000 Guineas Trial over seven furlongs.