U.A.E. Derby (UAE-G2) runner-up MASTER OF HOUNDS (Kingmambo) made a good impression during his first visit to Churchill Downs' track Thursday morning.

The Aidan O'Brien trainee cleared quarantine and went to the track at 8:30 with a number of other Kentucky Derby (G1) and Oaks (G1) horses. He trotted once around the course and then cantered another circuit.

Master of Hounds, who will be ridden by Garrett Gomez in the Derby, turned heads when he waited at the gap to go on the track.

"I thought he looked good and when we were walking around and we could see the American horses walking around. I thought he looked quite well," traveling head lad T.J. Comerford said. "He was looking well and he had a good shine on him."

Master of Hounds ran very well in Dubai and is O'Brien's first Derby horse since he debuted with a pair in 2002.

"I think it was always in Aidan's plan to come here," Comerford said. "We try to bring a horse that you think might handle it. I know the last time we brought Johannesburg and Castle Gandolfo. This horse ran so well in Dubai that maybe that sealed it that we would bring him here."

Aside from how he gets over the dirt, Comerford said he doesn't have any concerns about the laid-back colt.

"If he handles the dirt, that's the thing," Comerford said. "If he handles the dirt, he will run well. He broke well in Dubai. He was actually first out in that. He's no slouch. Hopefully, he will run well. I think he will."

Comerford said the colt traveled well on the dirt with Pat Lillis on Thursday.

"Pat rode him and he was happy with him," Comerford said. "That means a lot. He rides him every day and he knows the horse. Pat was telling Aidan that he was happy with him. That's all we can do."