LOUISVILLE, KY. – At precisely 7:46 a.m. Thursday, the last embodiment of mystique at the 144th Kentucky Derby emerged from his screened-off barn and made his way, finally, to the track.

Since he arrived at Churchill Downs on Monday night, this would-be European conqueror had been defined mostly by his absence. No one could lay eyes on him because he was confined to the quarantine barn. None of his connections showed up to speak for him at Tuesday’s post-position draw.

But the name Mendelssohn has nonetheless bubbled on the lips of fans and rival trainers alike. In lieu of appraising his physical form, they’ve spoken in awe of his globetrotting victories in California, Dubai and his home base of Ireland.

Most of all, they’ve debated whether he can finally bring an international flavor to the winner’s circle at the most coveted race in the United States.

Churchill officials have done everything they can to invite a steady flow of European, Japanese and Middle Eastern contenders to the Derby. They’ve made the UAE Derby in Dubai a near-automatic qualifier and created a series of preps in racing-crazed Japan. They envision more robust overseas wagering on the race and on Derby futures in subsequent years.

“It really adds to the event to have horses from around the world compete here,” said John Asher, vice president of communications for Churchill. “The fact that Mendelssohn is here and ready to go makes it a more exciting event and a bigger conversation piece around the world. Should he run well on Saturday, I think it’s all the better.”

There’s the rub.

Despite the open pathways, quality contenders have not streamed in from across the oceans. The last horse to train overseas in preparation for a Derby victory was Canonero II, who came from Venezuela in 1971.

Given the depressing Derby record of European-trained horses — 0-for-36, according to research by the Irish Times — it’s a given that some analysts and bettors will remain skeptical of Mendelssohn right up until post time.

Remember Arazi, they might say, the French horse deemed the “second coming of Secretariat” by Time Magazine. The betting public wagered as much on him to win the 1992 Derby as on the rest of the field combined. He finished eighth.

Just understand that if you’re viewing Mendelssohn as the next Arazi, you’re out of step with many of the best minds on the Churchill backstretch. They look at his victory in the Breeders’ Cup Turf Juvenile as evidence he can whip a good field. They see his stunning 18½-length victory in the UAE Derby, his debut on dirt, as proof of his brilliance. And most of all, they express deep respect for his trainer, Aidan O’Brien, his jockey, Ryan Moore, and the mighty Coolmore racing operation that stands behind them.

They are to European racing as the New England Patriots of Bill Belichick and Tom Brady are to the NFL or the New York Yankees of Joe Torre and Derek Jeter were to baseball.

“I’m not skeptical of anything Aidan and them do,” said Kentucky-based trainer Dale Romans, who will saddle two horses in the Derby. “That’s probably the best-run operation in the world. The way he ran in Dubai, even if he’s half that good, he’s still spectacular.”

“He’s trained by probably the best trainer in the world, and I don’t think he ships just to come for the Kentucky Fried Chicken,” said trainer Bob Baffert, whose Justify is the only horse above Mendelssohn in the morning line. “He’s very dangerous. He has brilliance.”

Baffert isn’t one to effuse over a fellow trainer, but he described the 48-year-old O’Brien as a “superior horseman” and “such a kind gentleman.”

The Irishman’s record in Europe looks like those of Baffert and Todd Pletcher here. And his horse ain’t bad, either.

“I like him a lot,” said jockey Mike Smith, who will try to beat Mendelssohn aboard Justify. “He might be better on the dirt than on the grass. Kind of looked like it that day in Dubai, didn’t it? So I don’t take him lightly. I think he’s the best horse they’ve brought over here.”

O’Brien has brought five previous contenders to the Derby, but his best result was a fifth for Master of Hounds in 2011. Moore rode his horse, Lines of Battle, to a seventh-place finish in 2013.

But the consensus is they’ve never come to Kentucky with a talent close to this one.

Mendelssohn drew a superstar price long before he demonstrated superstar potential on the track. Coolmore paid $3 million at a September, 2016 yearling sale for the son of 2016 Broodmare of the Year Leslie’s Lady and the late, great stallion Scat Daddy.

That infusion of cash brought tears to the eyes of breeders Fred and Nancy Mitchell, who run a modest operation at Clarkland Farm in Kentucky. Fred Mitchell was at Churchill on Thursday morning to watch Mendelssohn go to the track.

“He looked like he just skipped over it this morning,” the breeder said proudly.

Though Clarkland is only about 80 miles away, the Mitchells have never attended a Derby. “We said we’d never go unless we bred something that was capable of running in it,” Fred Mitchell said.

Mendelssohn took a little time to make good on Coolmore’s investment, winning just one of his first four races before he stormed the Breeders’ Cup last fall. O’Brien and other top European trainers have always been most successful on turf, so it was easy to overlook Mendelssohn in early discussions of Derby contenders. But he was bred to succeed on dirt and did just that in Dubai.

Baffert watched that day as the O’Brien-trained horse destroyed the excellent filly, Rayya, who would subsequently move to train in his California barn.

“That was a holy moly move right there,” he recalled.

Since then, the drum beat has only built as the American racing community has awaited Mendelssohn’s return to the state where he was bred. That journey was briefly diverted on Monday evening, when his transcontinental flight had to be re-routed to Indianapolis because of a reported paperwork error involving another horse on the plane.

O’Brien still had not arrived as of Thursday morning. His chief traveling assistant, Pat Keating, was left to give a brief update that “we couldn’t be happier with how he’s doing.”

Regardless, Mendelssohn appeared in the flesh, his dark bay coat covering a lean, taut frame. He was no apparition but a real horse to be feared.

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