Aidan O’Brien admitted his disappointment after River Tiber was ruled out of the Breeders’ Cup Juvenile Turf at Santa Anita.

The Wootton Bassett colt was expected to be a major player in the mile contest after claiming third in the Middle Park Stakes on his most recent run, but River Tiber was scratched on vets’ advice just hours before his intended engagement.

Stablemate Bolshoi Ballet was also taken out of Saturday’s Breeders’ Cup Turf and O’Brien was pragmatic in his response.

He told ITV Racing: “He (River Tiber) was being checked all week, he seemed OK and the vets have checked him this morning and weren’t happy with him, so that’s the way it is. Obviously that’s the rules and I suppose there’s no more to say about that.

“We’re visitors here and we’re very grateful to be here, rules are rules and they just weren’t happy with him today.

“Obviously they’re athletes and they don’t pull out the same way every day, like we don’t get out of bed every day the same, and he might have been slightly stiffer today than he was yesterday.

“When you’re training horses that does happen and every athlete in the world will tell you the same, it’s very fractional and I suppose it’s opinion. I suppose there was a different panel of vets checking them all week and just a different vet checked him this morning and he wasn’t happy, so that’s the way it was.

“Obviously when we came here we were happy to abide by whatever rules were going to be set in this state by the Breeders’ Cup.

“We’re disappointed for the lads (owners) really, they put a lot in but that’s that way it is.

“Whatever decision the authorities make in any sport, you just have to stand by it, you don’t always agree with it but somebody has to make the decision, sometimes it will fall for you, sometimes it won’t. With these horses today, it didn’t fall for us.”

Of River Tiber’s future plans, he added: “I’d say he’ll have a break – this obviously would have been his last run and he will be trained for the Classics next year.”

The Ballydoyle handler still won the Juvenile Turf, with Unquestionable taking the prize under Ryan Moore.

O’Brien’s runners were not the only horses scratched, with the Jessica Harrington-trained Givemethebeatboys taken out of the Juvenile Turf Sprint.

The handler admitted the experience could make her think twice about bringing horses to the fixture in the future.

She said: “He has not had a single issue all week – he has been examined at least three times a day, he has been out on the track, he has galloped, he’s done stalls, there are vets on the gallops.

“He went out this morning as usual, did a little trot to come back in and the vets came to have a look at him and they decided he was not entirely level on his off fore.

“I don’t agree with them – I see where they trot our horses up is not a level place, you trot on some mats and then you’re on sand.

“It would definitely (deter me from bringing horses back). I brought out what I thought was a very sound horse, I know they have to be careful but being careful or over the top are two different things.”