04/26/2011 12:22PM

Kentucky Derby: Stay Thirsty to have Dominguez aboard

Adam Coglianese/NYRA
Stay Thirsty, with Ramon Dominguez riding, wins the Gotham.

Jockey Ramon Dominguez will ride Gotham Stakes winner Stay Thirsty in the Kentucky Derby on May 7, owner Mike Repole said Tuesday.

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The riding assignment was firmed up after Uncle Mo worked strongly Tuesday morning at Churchill Downs with John Velazquez, who will ride Uncle Mo in the Derby.

Had Uncle Mo not made the Derby, Velazquez likely would have ended up on Stay Thirsty, since he is the first-call rider for Todd Pletcher, who trains both Uncle Mo and Stay Thirsty. But now both spots are filled.

Still to be determined are Derby riding assignments for expected starters Master of Hounds and Twinspired.

Still without a confirmed mount is jockey Calvin Borel, winner of the Derby three of the last four years and a finalist on the ballot this year for the Hall of Fame.