Johannesburg, who is scheduled to run in a one-mile dirt race at Lingfield on April 6 as his only prep for the Kentucky Derby, was shipped to England for a work over the track Tuesday and went 6 furlongs in 1:12, according to trainer Aidan O'Brien"He did it in a canter," O'Brien told The Blood-Horse from Lingfield. "We worked him in company with Rock of Gibralter and Shoal Creek. He settled nicely behind both horses and was kept on the bridle. He finished up very well and did it easily. We were very happy with the work."Another Coolmore colt sent to Lingfield to work was Castle Gandolfo, who went his 6 furlongs in 1:14, also in company with two horses. "He's nominated to the Triple Crown, and if we can get in, there's a good chance we'll run him in the Kentucky Derby with Johannesburg."Castle Gandolfo certainly has the credentials. The son of Gone West, out of the Northern Dancer mare Golden Oriole, won his first two starts, including the group III Beresford Stakes at a mile. Following a second to High Chaparral in the group I Racing Post Trophy over a mile at Doncaster, he was sent to France where he rallied to finish second to stablemate Ballingarry in the 1 1/4-mile Criterium de Saint-Cloud.