Edgar Prado has the mount on British import Dr Greenfield for the Belmont Stakes (gr. I) as Jerry Bailey will ride Stronach Stable's Thunder Blitz in the 1 1/2-mile classic, according to a Sporting Life report."Bailey has an obligation to Frank Stronach, so Prado, one of the top riders on the New York circuit, will ride him," Dr Greenfield's trainer, Gerard Butler, told Sporting Life. "He rides an awful lot for Team Valor and they rate him very, very highly. He's a very, very strong rider, which is more beneficial than anything else -- the horse requires a strong rider."Dr Greenfield (Dr Devious--Memory Green, by Green Forest) has won three of four career starts, including the Philip Leverhulme Dee Stakes. The Team Valor colt will be saddled by Butler for the Belmont, and then remain in the United States in Bill Mott's barn.Dr Greenfield worked after racing was conducted at Lingfield Saturday with jockey Kieren Fallon in the irons, according to the report."More than happy," said Butler of the work. "Kieren's happy and so I'm happy. That's his last piece of work. He'll do one piece out of the stalls at home and then that's the job done."