It was January weather on the gallops at Ballydoyle on Monday, but the first Saturday in June was the focus of all thoughts as many of Aidan O’Brien’s stable stars, including City Of Troy, the colt with a lofty reputation to redeem after his no-show in the 2,000 Guineas, went through their morning exercise routine in the run-up to the Derby at Epsom.

City Of Troy was pushed out to 8-1 for the Derby after he beat only two of his 10 rivals to the line at Newmarket this month, shattering the aura of invincibility that had surrounded him after an unbeaten juvenile campaign. But he has since edged his way back to the top of the market and there has been a similar journey of shock, reflection and then renewed confidence for his trainer.

Related: Time will tell if City Of Troy’s 2,000 Guineas flop was just an aberration | Greg Wood

The belief at Ballydoyle now is that “a wrong few seconds” at the starting stalls cost City Of Troy his unbeaten record. “I’m not sure we’ve ever sent a horse to the Derby with as much ability as this,” O’Brien said on Monday. “Sometimes, things don’t work and I would always say that it’s my responsibility to make sure that it works. When it doesn’t work, we might’ve done our homework, but we didn’t do it all properly. It all happened wrong [at Newmarket], but it will make it very interesting the next day.

“When he went into the stalls he should have been relaxed, but he was revved up. Obviously, his mind wasn’t in the right place because he is a very good-natured horse, unusually good for a colt, very calm and relaxed. The Guineas was not to be and I’d say I didn’t have him prepared properly, but what we learned in the Guineas we hope will help us to prepare him for the Derby.”

The immense disappointment of City Of Troy’s odds-on reverse at Newmarket was keenly felt by his connections and the general racing public alike, not least because the noises emerging from Ballydoyle had been overwhelmingly positive. O’Brien, though, has no regrets about the upbeat buildup to City Of Troy’s first run for six months.

“There’s no point in going to the races thinking that something’s going to happen that you’re not after telling anyone else about,” he says. “We tell everybody our feelings and our dreams and sometimes you get there and it doesn’t happen. We always think there’s a reason why it didn’t happen, so we delve into the reason [and] at the moment, we’re back dreaming again.”

O’Brien can draw on 30 years’ of experience and almost constant success as he tries to rationalise what happened at Newmarket. There is detailed information arriving from all manner of sources, from interpreting the instant impressions of work-riders – “I can tell the different ways they all say OK” – to quantitative assessments such as timed gallops, weights and blood counts.

“We have heart monitors, we have times, we have weights, bloods, everything now. All those things are being monitored,” O’Brien says. “When we are happy that a horse is in the right place mentally and physically, if all the other things stack up, you’ve a big shot and it’s going to be hard enough to beat you.”

O’Brien is also in a position to ensure City Of Troy has back-up at Epsom, with Los Angeles, the winner of Sunday’s Derby Trial at Leopardstown, and Capulet, who took last week’s Dee Stakes, among other likely members of the Ballydoyle team before the final trials at York this week. But City Of Troy remains the yard’s leading candidate as O’Brien seeks to become the first trainer to saddle 10 Derby winners.

“What you can’t measure is mind and determination and that’s the most important thing in horse or human,” he says. “Do they want it, do they want to get better? Are they going to work hard enough to make themselves better? That’s inside and it’s really only when you start training them that you see whether that’s there or not.

Beverley 2.15 Assertively 2.45 Lochaber 3.15 Digital 3.45 Herakles 4.15 She’s Got Bottle 4.45 Straight A 5.15 Solar Bentley (nb)

Southwell 2.30 Happy Du Mesnil 3.00 Bbold 3.30 Yakaleo 4.00 Cyclonic 4.30 Hiconic 5.05 Just Gino 5.35 Giulietta

Ayr 6.30 Mostar Dreams 7.00 Busby 7.30 Slainte Mhath 8.00 Kelpie Grey 8.30 Highfield Viking 9.00 Billy Bathgate

Chepstow 5.40 Mayz 6.10 Ravenglass 6.40 Sonic Si 7.10 Notre Maison 7.40 Connie’s Rose (nap) 8.10 Letter Of The Law 8.40 Cherryhawk

“You can have the most beautifully bred horse and the most beautiful mover, but if he doesn’t want it, it won’t happen, because when you really want it, he’ll say no. You can get a freak that mightn’t have a pedigree and it mightn’t have the body, but they have it inside and they will surprise you.

“That’s what makes this whole thing so fascinating and it’s why everyone has a chance. What’s inside is the hardest thing to measure but, for me, it’s the most important.”