AIDAN O’Brien has admitted that stable jockey Ryan Moore “would find it very hard to get off” Chester Vase winner Benvenuto Cellini for next month’s Betfred Derby, unless Constitution River also lines up in the Epsom Downs classic. As the Ballydoyle maestro assesses his squad of three-year-olds ahead of the Betfred Derby Festival, he says “nothing is written in stone”.

Speaking at a media morning arranged by the Jockey Club, the trainer, who is the most successful in the race’s history with a record 11 victories to his name, said: “Epsom is the ultimate test in every way. The Derby is the ultimate test because of the contour of the track, the atmosphere and the strain, both mentally and physically. It’s a very, very tough, unique place and that is why the Derby is what it is. It engages the whole thoroughbred breed and tests them in every way.

“There is no other race or track anywhere in the world that can do it like that. There is nowhere to hide in the Derby. You have to have pace, ability, you have to stay and you have to be like concrete, mentally. What was the best Derby winner we ever had? I would say it was Galileo. And he proved to be probably one of the greatest stallions ever. That’s what Epsom does. It’s very tough, but you will get the blood that you really want going forward.”

On his Derby contenders, he added: “At the moment, we are looking at the horse that won the Chester Vase, Benvenuto Cellini, for Epsom. We are also looking at the horse that ran on Sunday, Pierre Bonnard, for Epsom.”

Benvenuto Cellini 3yo ch c Frankel - Newspaperofrecord (Lope De Vega)

We think he’s a mile and a half horse that wouldn’t be going any further and he could come back to a mile and a quarter. Pierre Bonnard would have no problem going up to a mile and six (furlongs). Benvenuto Cellini has speed and class as well. He has a big open stride and looks like a horse that you would be surprised if he didn’t get a mile and a half, but at the same time, you would be surprised if he gets much further. I think Ryan would find it very hard to get off Benvenuto Cellini, but I would imagine if Constitution River went (for the Derby), he would probably get off of Benvenuto Cellini. But it wouldn’t be written in stone.

Constitution River 3yo b c Wootton Bassett - Chuppy (Le Havre)

Constitution River could possibly go to France - it’s not written in stone. Constitution River went to Chester knowing that he could be an Epsom or a French horse. And we were happy that it was a mile and a quarter, just in case he was going to go to France. The only thing is, if he goes to France, he’s only left-handed so far – he didn’t go right-handed yet.

We felt, and the way it was looking, he looked very different going through all his work. He looked very good last year. He had a good long break. And what happened is we were kind of hoping and expecting that it could happen. He seems to have come out of the race well.

Constitution River is one of those mile-and-a-quarter horses that could get a mile and a half, but you couldn’t be sure. If you were riding him over a mile and a half, you’d be riding him a bit patiently. But he has a lot of speed and a lot of class.

Pierre Bonnard 3yo b c Camelot - Sultanina (New Approach)

We think Pierre Bonnard is going to step up again. He’s going to get a mile and a half and could get further. He was a massive, big horse and we purposely let him get as big as we could over the winter and as strong as we could, because we didn’t want him to turn into a shell early. So, we felt we had to run him (in the Ballysax Stakes).

The race went a bit wrong and he was needing to run. Because he was where he was, we couldn’t go, say, and attack into him and have him really ready for yesterday, because then we wouldn’t carry on to the Derby. So, we had to do it gently. We stripped him back a bit more for Leopardstown (last Sunday). The pace was probably too slow for him, but he still ran very well. I would think and we think that he would step up big time next time going a mile and a half.

Diamond Necklace 3yo b f St Mark’s Basilica - Prudenzia (Dansili)

Amelia Earhart 3yo b f Camelot - Venus De Milo (Duke Of Marmalade)

At the moment, we’re thinking that Diamond Necklace could go back for the Prix de Diane and we’re thinking Amelia Earhart is going to Epsom. Amelia Earhart has a kink in her, and we saw her a few times do it last year, like she’d go there and she’d go left or right. So that’s why she had the headgear on her at Chester.

We tried everything through the winter with her and did everything, and this (wearing a hood and blinkers) is what we landed on. This was the way and this is what she behaves the best in. That’s why she ran in that. And it didn’t make any sense, because one is to slow her down (hood) and the other is to drive her forward (blinkers). Sometimes things don’t make sense. If they work, you just do them. So, whatever way she thinks, that calms her down the best. And that’s when she gets into the right place. Amelia Earhart did behave very well in Chester, which is probably as close to Epsom that you will get.

Precise 3yo ch f Starspangledbanner - Way To My Heart (Galileo)

We always had in our head that Precise could get the Oaks trip. And we always had it in our head she could go to the Irish Guineas and come back two weeks after to the Oaks. And this year, there’s two weeks again. When there’s one week you can’t do it, but you can do it with two weeks, because Minding and all those did it.

So, it’s possible. If Precise does run well in the Irish Guineas and goes for the Oaks, it would be another difficult one for Ryan. He’d have to ride Precise very patiently, where he knows Amelia Earhart will get it. And I think that’s all the kind of intrigue about the whole thing.

Christmas Day 3yo b c Camelot - Beauty (Sea The Stars)

Christmas Day (finished third in the Dante at York on Thursday) was always a very legitimate horse. We were going to France to the Group 1 with him last year that Pierre Bonnard won and he got a temperature and he had to stop.

He was off then, and since then, he’s ran in the Ballysax and he won that. He beat Pierre Bonnard, so, it’s going to be interesting. And I’d say he’s probably stepped up from the Ballysax.

DESPITE repeated success at the highest level, Aidan O’Brien insists the team at Ballydoyle takes nothing for granted.

“We’re never surprised by anything. Believe me, in any way, the weirdest, strangest, maddest, craziest things happen.

“But we do our best for it to happen. We think as clearly as we think we can, but then you go back and you say, ‘why the hell did I do that’ or ‘why did I think that?’ We don’t take one race for granted. All those Group 1s are so difficult to win, I can tell you.

“Everyone will be totally focused all the way and we’ll do our best to win them, but that’s not a given, ever. The horses came along gently from the time they started running at two. These weeks are always their aims.

“There’s a lot of lefts, rights and everything in between, and there’s other horses as well. But I would never be surprised. Obviously, it would be disappointing if you don’t win. You do your best for it to happen, but you accept the result and move on.”

Chester trials

O’Brien also explained why the Chester classic trials are so informative, adding: “There’s only one reason we go to Chester. The ground is usually very good there. It’s usually very safe.

“Horses come over very well. They have to get quick feet. They have to start early. They have to go forward. They have to hold a position. And they have to come up the straight. And they’re running back into the crowd again. There’s usually a massive atmosphere there. It’s kind of a colloseum effect.

“You have to go there to witness it. To see it, but the horses feel it.

“They’re coming from the stable yard, they have to come out, the train is going by, and the people are roaring. It’s mad. On both sides as well. It’s a busy infield. You’re in a crowded parade ring and there’s people. Everyone is enjoying themselves. The bars are all around the parade ring.

“All the things you want, really. It’s a festival. And it’s an unbelievable atmosphere. And, like we say, the horses feel it. It’s a preparation for them. It’s obviously not a full-blown experience. But it’s close. It’s on the way up to it.”

A proper race

O’Brien is also excited for next month’s Coolmore Coronation Cup, which is worth £1 million this year. He said: “We hope that Calandagan will run in the Coolmore Coronation Cup and hopefully it’ll be a good race. Hopefully, Lambourn will be okay for it, and he’ll come out of his last race well and hopefully Jan Brueghel will be okay for it too and he’ll come out of his last race well also.

“And then Calandagan comes over, so that will make it a proper race. And it’ll be exciting then for everyone to see what’s going to happen, won’t it?

“We want all the big horses to turn up on all those big days and then everyone can have an opinion.

“Chester was perfect for both Lambourn and Jan Brueghel. We were very happy with Jan Brueghel (in the Ormonde), I thought it was a lovely run.

“I thought Ryan did well on Lambourn (in the Huxley Stakes), because he never got to sit for one stride. When you see it, it’s unusual that a horse could do that and still win. Like, he rooted him out, and he was going all the way and kept digging.

“He probably didn’t stay in the Leger. In all fairness, he had a very tough season going into the Leger, so he was entitled to hold up the white flag at that stage.

“But I tell you, he’d be a fair horse to go off in front there now. He’d be a brave man to let him go, wouldn’t he? I wouldn’t like to be giving him too much rope around Epsom. So, it will be an interesting race.

“I think Ryan would ride Jan Brueghel. The horse got sick after he won last year’s race. He started choking on a piece of hay one day, nearly died, and he got pneumonia. So that’s why you didn’t see him. He has done very well to get back to where he is.”