The ground yesterday afternoon was described as soft, heavy in places, and O’Brien believes the 2000 Guineas and Epsom Derby winner may not be seen to best effect.
A long odds-on shot with the bookmakers, Camelot is being talked of as the first potential Triple Crown winner since Nijinsky in 1970.
First, though, Camelot has to come through his next test unscathed.
O’Brien has won the last six renewals and nine in all.
“Camelot is a very good-actioned horse. He obviously won the Guineas on slowish ground but it was lovely, fast ground at Epsom,” O’Brien said. “We would obviously have to have concerns if it went very soft and it is not ideal and the more it dries out, the better it is for him.
“Paul (Hensey, Curragh manager) thinks it will be dry enough up to race time and obviously we hope that is the case.
“He’s been special all along. He won the Racing Post Trophy last year, then he was very impressive in the Guineas and in the Epsom Derby which was his last start.
“He’s always shown a lot of speed, a lot of class, a lot of courage, so he’s just one of those unique horses that come along very rarely.”
As is usual in the Classics, O’Brien has multiple contenders but there is a slight doubt about one of his intended runners, the Sandown Classic Trial winner Imperial Monarch.
“We hope to run Imperial Monarch but when we were shoeing him he just had a slight little pulse in his foot, we hope that doesn’t turn into anything,” he said.
“We hope to run him and the horse that was third in the Epsom Derby (Astrology).”
Hensey does not envisage too much more rain before Saturday evening’s new post time at 7.40pm. Nothing much has changed all day, it’s been soft, heavy in places,” said Hensey on Friday.
“It’s been dry most of the day with sun and wind. We had one heavy shower but it didn’t amount to much and it’s been bright and sunny since.
“We hope it will be dry for the rest of Friday and we’ve got a similar forecast for tomorrow with a few floating showers, they are very localised.
“The ground could dry up to soft with maybe yielding to soft the best case scenario.”
Johnny Murtagh faced a difficult choice with Born To Sea and Akeed Mofeed both representing his boss John Oxx, but he stayed loyal to Born To Sea.
“I just think the fact that he’s race-fit put things in his favour,” said Murtagh.
“We didn’t think he’d want a mile and a half at first but he stayed on very well in the Irish Guineas from a long way back and at Ascot I thought turning in I had a good chance, but he just stayed on rather than quickened.
“His dam (Urban Sea) has produced a lot of middle-distance horses and she has a huge influence. Horses like Galileo, Black Sam Bellamy, Sea The Stars and All Too Beautiful all stayed a mile and a half well.
“At the start of the year we didn’t think he’d want to go this far, but maybe he does.
“I still believe he’s a Group One horse.”
Akeed Mofeed has not been seen since September due to a series of little niggles, but he was a big talking horse through the winter.
Bruce Raymond, racing manager to Akeed Mofeed’s owner Jaber Abdullah, feels the race will set the horse up for the rest of the campaign.
“We’re getting him on the track at last. John (Oxx) assures me he’s as fit as he can get him without a run,” said Raymond.
“We’re hoping for a big run from him and hopefully it will set him up for the future.”