AIDAN O’Brien stepped out of Barn 17 on the Churchill Downs backstretch at little before 7 a.m. Friday, following his four Ballydoyle charges to the racetrack and scouted out a good spot to watch Mendelssohn turn in his last bit of work before Saturday’s Kentucky Derby.

O’Brien, with Mendelssohn’s co-owner Derrick Smith, jockey Ryan Moore and members of the Coolmore and Ballydoyle team in tow, settled on the outside elevated porch of the backstretch clocker’s stand.

As Seahenge, Threeandfourpence, Mendelssohn and Deauville jogged and walked along the outside fence, O’Brien called a quick audible, dashed down the steps and made his way up the backstretch.

He found another spot near the backstretch media centre – a much quieter place Friday than any other day this week with a big card topped by the Kentucky Oaks on tap – but spun on his heels again, thought he found another spot near the backstretch gap where Bob Baffert watches training before eventually returning to the porch of the clocker’s stand.

The entire ordeal lasted five minutes – from the time a security guard told onlookers to “make way” along the horse path from Barn 17 until O’Brien pressed his binoculars to his face and chatted on his iPhone to head traveling lad Pat Keating on the ground below.

Mendelssohn and his stablemates made their way around the Churchill dirt track during that time, putting in a similar walk/jog before coming to a stop at spot not far from the finish line in front of a tent emblazoned with Vineyard Vines logos.

After standing for a moment the quartet cantered single file in the middle of the track while joggers reversed along the outside rail and gallopers and breezers took to their inside. The group did just a touch more work than Thursday, their first trip to the track after clearing quarantine Wednesday afternoon.

“He just did a gentle canter yesterday and just did a little bit quicker today, but it’s really just showing him around the place and the track,” O’Brien said to a small group of press gathered outside Barn 17.

“We’ve been very happy with him. We haven’t overdone him. It’s only been five weeks since Dubai and of course four weeks with the travel. He had a good, strong race in Dubai. He’s here fresh, rather than (having been) hard on him, if you know what I mean.”

O’Brien and Moore arrived in the US on Thursday and will stay through Saturday’s Derby, this country’s top prize and one of the most coveted races in the world.

Five horses from Ballydoyle have made the trip from Ireland to Louisville to run in the Derby, the best finish a fifth by Master Of Hounds in 2011.

American and European champion Johannesburg was O’Brien’s first Derby starter, finishing eighth in 2002. O’Brien has experience at Churchill Downs, winning two Breeders’ Cup races in 2011, but he’s never been to the Derby.

“It would be something that we couldn’t really dream of,” O’Brien said of the possibility of winning with Mendelssohn, the race’s 5/1 second choice on the morning line. “We feel so privileged to be here, to have a horse here and to compete. It’s an incredible race, an incredible place and culture here.”

Mendelssohn seems to relish the surroundings, continuing to display his vocal personality.

O’Brien said that’s encouraged back home, with every horse at Ballydoyle being allowed to develop their own trademark. Mendelssohn let a few roars rip on the short walk from the barn to the track, turning heads as always, but remained focused and in control.

Training under cloud cover with just a threat of rain, and going to the track about an hour earlier than Thursday, Mendelssohn barely cracked a sweat Friday morning under exercise rider Dean Gallagher.

“Even though he’s vocal, he cries out and calls to horses, he’s not coltish, he doesn’t draw or doesn’t show in that way,” O’Brien said. “It’s more of a mental thing than anything. As we were training him last year when we put the blinkers on him it totally focused his mind, it’s amazing that an inch at either side of his eye, it totally changes his focus. That’s the way he has been so far.

"What you see there is he was the same in Dubai before he raced and we saw last year, the minute the blinkers went on he totally focussed. We don’t want to change too much. He’s slowly growing up mentally and physically.”

READ SEAN CLANCY'S HORSE-BY-HORSE KENTUCKY DERBY PREVIEW IN THE IRISH FIELD THIS WEEKEND