Early morning rain made for a dreary backside at Churchill Downs on Friday morning, with news and developments concerning Kentucky Derby horses in short supply.Trainer Bobby Frankel had a brief scare when Toyota Blue Grass Stakes winner Peace Rules acted up coming off the track after jogging over the wet track. Peace Rules kicked and reared up after going through the gap that leads the parking and barn areas, causing exercise rider Tony Graell to jump off and continue his hold on the son of Jules."It is a very dangerous thing for a horse to get loose here, because of all the cars and parking area on t he backside," Frankel said. "If he had gotten loose, he could have really gotten hurt."Frankel said he initially wanted to gallop Peace Rules and stablemate Empire Maker, the likely Derby favorite, but opted to only jog them as a result of the sloppy track. "I try to avoid wet tracks because they can only hurt your horses," the Hall of Famer said. "They don't get much out of it when it is like this because they are just slapping around out there. I am sure this track will be fine by tomorrow."In other Derby developments, Supah Blitz arrived via van from Florida and trainer Bob Baffert said Senor Swinger, who worked on grass for the first time Tuesday, would run in the Crown Royal American Turf on the May 2 Kentucky Oaks card.