The Galileo filly has already proven herself to be brilliant over a mile but steps up another four furlongs at Epsom tomorrow.
Having won the 1000 Guineas at Newmarket, she was beaten in the Irish equivalent by Jet Setting but it came to light after the race that she had banged her head in the stalls, injuring her sinus.
“She’s in good form and we’re happy with her since the last day. Obviously she hasn’t done much, but we’re happy with her,” said O’Brien.
“We can’t be sure about the trip by any means. She has form in soft ground but going a mile and a half first time, you wouldn’t be sure about it.
“It’s her first time over a mile and a half and we’re looking forward to seeing her run over it.”
O’Brien has three strings to his bow and both Somehow and Seventh Heaven won their trials at Chester and Lingfield respectively.
“Somehow was very green at Chester. She handles an ease in the ground and it looks like one that will get a mile and a half,” said the Ballydoyle maestro.
“We’re hoping that she has learned a lot from Chester and we think that she has come forward.
“Seventh Heaven looked green and a bit at sea in front at Lingfield. She was probably more green than anything.
“We think she has come forward. I don’t think she wants the ground to get too soft, but she’s in good form.”
Ryan Moore is on Minding and is not too put off by her defeat at the Curragh.
He told www.betfair.com: “My high opinion of this filly is well-known and I was gutted that she got beaten in the Irish 1,000 Guineas. But it was a late decision to run in the race after Ballydoyle was found to be off-colour and the fact that she banged her head coming out of the stalls didn’t help.
“However, ultimately, I think that she just found the ground too soft for her against a filly who relished the conditions, and the pair did pull 10 lengths clear of the third. So, yes, you could say that she hasn’t had an ideal preparation for this race and that she would want better ground, though it can dry out very quickly here. And she obviously has her stamina to prove.
“Turret Rocks is the main form danger to me on her Boussac second and she ran well enough when sixth to Minding in the Guineas, but she has always been thought of as a good or fast ground filly so that would have to be a concern.”
While four horses were supplemented for Saturday’s Derby, only one was added to the field for the Oaks in the shape of Godolphin’s Skiffle.
The Dubawi filly only made her debut in May when third in an Ascot maiden, but just two weeks later she stepped up markedly to win the Height Of Fashion Stakes at Goodwood.
Connections were leaning towards the Ribblesdale at Royal Ascot, but Minding’s defeat in the Irish Guineas changed their thinking.
Her trainer Charlie Appleby said: “She’s a nice filly and she’s done nothing wrong so far.
“She’s getting stronger all the time and we think she deserves her place in the race.
“I fully respect the favourite (Minding). She was obviously beaten last time, but there were reasons for that with the conditions and she’s a very good filly.
“Hopefully our filly can continue improving and if she runs into a place, I’ll be delighted.”
Hugo Palmer has already tasted Classic glory this season with Galileo Gold and goes in search of another success with the Frankie Dettori-ridden Architecture, who was second in the Lingfield Oaks Trial.
“Fillies don’t have quite the same arrogance, but she’s not without kinks,” Palmer said, referring to Galileo Gold.
“Her rider has to take a lead rein out in the morning and get off her going home. She makes some extraordinary shapes but, touch wood, she’s beautifully balanced and lands every triple salchow with absolute precision. Now I’ve said that, she will probably end up on her bum tomorrow.
“She handled softish ground very well at Epsom’s Breakfast With The Stars last week. There’s a difference between galloping and running on it, but she also won her maiden on soft ground last year. If Minding is as brilliant over a mile and a half as she is over a mile, then we are all in serious trouble. However, I feel that there is every chance that she won’t stay, on pedigree and style of racing, and that is obviously my hope, too.”