The two fillies earned the right for Classic glory after coming through their trials with flying colours.
“At this time of year horses can change a lot. Some improve, some don’t – I will ride them this weekend and then sit down with John and make a decision,” Dettori said at the annual Breakfast with the Stars event at Epsom on Tuesday.
“They both won their trials very easily. I don’t want to put any names on my mouth at the moment, I’m pretty open minded and will make a decision this weekend. They are two nice fillies.”
Mehdaayih will be supplemented for the Oaks to join her John Gosden-trained stablemate.
Gosden said: “The plan is to supplement Mehdaayih. The owners are very keen to do so and so are we.
“Anapurna has come out of Lingfield in great order and she is in the Oaks, therefore she will be left in to be running.
“They are still relatively young and I couldn’t be happier with both of them.”
Gosden said it was more likely Musidora second Entitle will wait for Royal Ascot.
“Entitle is more likely to go to the Ribblesdale,” he said.
“We’ve been happy with her since the Musidora, but it comes awfully close to Epsom this year. I think we would like to leave her for the Ribblesdale.”
“We are very happy with her, we always thought she would be a middle-distance filly and from early on through the winter and into the spring we always thought she would be our main Oaks filly,” said the Ballydoyle handler.
“There could be a couple of others and we could run a filly called Fleeting, who ran in the Guineas. Hermosa is going to the Irish 1,000 Guineas then after that she will step up to a mile and a quarter in the French Oaks.”
“It was not a case of coming here letting her loose, kicking her in the belly two from home and finding out how good she is,” he said.
“She worked on Saturday morning and ran in the Lingfield Oaks Trial. Fitness is not an issue, she is ready to go.
“It was really a training exercise and I was delighted how she moved and going through the line, but it was a controlled exercise and it will do her the world of good.”
Varian will wait until the weekend before announcing whether Musidora winner Nausha will take her chance.
“No decision will be made probably until the weekend regarding Nausha’s participation. She only ran last week and had a tame end of the week,” he said.
“She cantered on Monday morning and looked in great form. I really want the rest of the week to gauge her condition.
“She has the French Oaks as an option and we might be leaning slightly to at the moment, but I wouldn’t be standing here ruling her out of Epsom. All options are open.”
“She has done very well since Chester. I was very pleased with her work this morning,” said Beckett.
“She went six furlongs on the grass and everything went to plan. It was a nice, even bit of work and she will go straight there now.”