"He took a bad step at the wire," said Hall of Fame trainer Bob Baffert, who was inspecting horses at the Ocala Breeders' Sales 2-year-olds in training sale in Florida and was notified of the catastrophic injury by his assistant, Jimmy Barnes.
"It's very sad," Baffert said. "He was a neat horse. His stall is right outside my office. I would see him every day. You get attached to them and something like that happens; it's just tough. You never know what's going to happen."
The colt had worked five furlongs Monday in company with Restoring Hope when he was injured.
"He had a great mind, he had speed, he was sound," Baffert said. "He always showed up. He never ran a bad race."
In addition to the Smarty Jones win, Mourinho placed second in the Speakeasy Stakes and Bob Hope Stakes (G3). He won two of five career starts and earned $179,360.
Mourinho was purchased by Danny Pate for $30,000 from the Select Sales consignment to the 2016 Keeneland September yearling sale and was then pinhooked into last year's OBS March sale of 2-year-olds in training by De Meric Sales where he was purchased by bloodstock agent Kerri Radcliffe on behalf of Phoenix Thoroughbred for $625,000.