The 4-year-old gelding named Siempre Mo is entered in Saturday's sixth race, a $54,000 allowance race. He will be ridden by Joy Scott.
The Los Angeles Lakers teammates purchased 25 percent of the gelding at a team charity auction in April. Part of their deal is that neither Bryant nor Gasol pay any expenses in the horse's care and training. Santa Anita CEO Mark Verge and Chris Quinn, also an executive at Santa Anita, are the horse's other owners.
Siempre Mo won a $25,000 claiming race in his last start. He's trained by Doug O'Neill, whose colt I'll Have Another won the Kentucky Derby and Preakness, and will try to win the Triple Crown when he runs in the Belmont Stakes on June 9.
Bryant and Gasol's horse will carry gold silks with a purple Lakers emblem and a purple cap.