Preakness winner Shackleford will be retired at the end of the year and stand at stud at Darby Dan Farm in Lexington.
The farm said Thursday the 4-year-old is in training for the Carter Handicap at Aqueduct on April 7, with trainer Dale Romans hoping for a final race in the Breeders' Cup in the fall.
Shackleford was the leading 3-year-old money earner. In addition to beating Kentucky Derby winner Animal Kingdom in the Preakness last year, Shackleford finished second in the Florida Derby, Haskell Invitational and Breeders' Cup Dirt Mile. He has three wins in 13 career starts and earnings of $1,985,803 for owners/breeders Mike Lauffer and Bill Cubbedge.