Jerry Moss and his wife, Ann, had announced Zenyatta's retirement after her dramatic last-to-first victory on Nov. 7, 2009, at the Breeders' Cup Classic at Santa Anita, Calif.
Saturday, Jerry Moss said the undefeated 6-year-old daughter of Street Cry, who is unbeaten in 14 career starts, will run in 2010.
"We saw her gallop, I talked to Ann, then I talked to (trainer John Shirreffs) and she looks too good," Moss said. "It's what she likes to do and that's what we decided to do, so we're going to run her."
Zenyatta and Preakness Stakes winner Rachel Alexandra will vie for Horse of the Year honors Monday at the Eclipse Awards dinner in Beverly Hills.