Skeeter Johnston, from the polo-playing Johnstons of Cleveland, Tn., is in critical condition after being trampled by a horse in Florida, the South Florida Sun-Sentinel reported.
The incident happened during a practice game Wednesday morning at the International Polo Club Palm Beach in Wellington.
The son of Summerfield Johnston, former CEO of Coca-Cola Enterprises, the younger Johnston was getting ready for Friday's Stanford U.S. Open game.
The report says he collided with another player and was trampled. He suffered two broken legs, a broken pelvis, dislocated hip and broken jaw.
He was flown by helicopter to Delray Beach Medical Center.
The newspaper said he underwent surgery late Wednesday to alleviate swelling from the brain.
He is a player-sponsor for the Skeeterville team.
The newspaper said his sister, Gillian Johnston, player-sponsor of the Bendabout team, did not play in Wednesday's U.S. Open game against White Birch due to the accident.
She was at her brother's bedside with other family members.
Skeeter Johnston had competed in three U.S. Open finals.
The Sun-Sentinel said he is co-founder of the North American Polo League and principal partner in a new high-goal polo facility, the Flying H Polo Club in Wyoming.
His family has the Bendabout Farm outside Cleveland.