BALTIMORE (Reuters) - Surprise Kentucky Derby winner Mine That Bird will run in the Preakness Stakes, the second leg of U.S. thoroughbred racing's Triple Crown, the gelding's trainer said Monday.

Trainer Chip Woolley had wavered because the mile-and-three-sixteenths Preakness at Pimlico racecourse on May 16 is the shortest of the Triple Crown races and Mine That Bird performs better at longer distances.

"You cannot have a Triple Crown winner without having the Derby winner in the Preakness," Woolley told the Pimlico racecourse website (www.pimlico.com).

"That played into our decision but the horse looks super. I have never been to Baltimore, but it looks like I won't be able to say that in a few days."

Kentucky-bred Mine that Bird, a 50-1 longshot ridden by Calvin Borel, won the Derby Saturday by 6 3/4 lengths, one of the biggest upsets in America's most celebrated race.

Papa Clem, who finished fourth in the Derby, will also run in the Preakness.

(Reporting by Steve Ginsburg; Editing by Justin Palmer)