Gleneagles familiarised himself with the dirt at Keeneland on Thursday morning in preparation for the Breeders' Cup Classic on Saturday night.
The Aidan O'Brien-trained dual 2000 Guineas winner will be heading into the unknown as he races on the surface for the first time and also tackles a mile and a quarter.
He has had an interrupted summer campaign having been ruled out of a number of engagements due to unsuitably soft ground, with only a last-minute decision leading to him running in the Queen Elizabeth II Stakes at Ascot on Champions Day, where he was sixth to Solow.
Under refreshingly clear skies, the Galileo colt was partnered on the main track by Joseph O'Brien, who said: "It's impossible to tell how he will handle the dirt, but what I would say is when he stretched his legs this morning he was in very good form and moving well.
"The dirt is still a bit sloppy, but better than it was and they are saying there will not be much more in the way of rain.
"My horse has a lot of pace, he's a good mover who travels and can quicken up and while it is a shot into the dark, he has a great constitution.
"I think we'll know after a couple of furlongs, if he's travelling and happy he's in with a shout."
The presence of Gleneagles in the Classic sets up a mouthwatering showdown with Bob Baffert's Triple Crown hero American Pharoah, who was also put through his paces in what was an eyecatching piece of work.
