India, May 2 -- The Puma, one of the top horses to watch at Churchill Downs in Saturday's Kentucky Derby, is out. His trainer, Gustabo Delgado, confirmed the news, adding that swelling was discovered in the horse's leg. An alternate will not take The Puma's place in the starting gate.

"It's just really bad timing," Delgado told Churchill Downs' Kevin Kerstein.

Just hours before the race was set to begin, The Puma was officially withdrawn, shrinking the field from 20 horses to 19. Delgado said on Saturday morning that the Grade 3 Tampa Bay Derby winner had developed swelling caused by a skin infection.

"We discovered some swelling in his leg due to a skin infection," Delgado told Churchill Downs' Kevin Kerstein. "It's incredibly disappo...