Lyric Of Light and Discourse put unbeaten records on the line as they make their first start since their juvenile year in Sunday's QIPCO 1000 Guineas at Newmarket.
The former completed a hat-trick in the Fillies' Mile over this course and distance in September.
Trainer Mahmood Al Zarooni believes Dettori will have to play his cards late.
He said: "She won a Group One last year and proved she's a nice filly.
"She worked on the Rowley Mile (at Craven meeting) and she worked very nicely.
"The ground was a bit soft, which she doesn't really like.
"I'm very happy with her and she is a very nice mover. She's professional and she has a good kick and a good turn of foot.
"In her last piece of work, when Frankie (Dettori) asked her to go past her lead horse, she didn't want to do it, so you have to force her and then she does it.
"She wants something in front of her to chase."
Discourse has yet to be tested at the highest level, but oozed class when winning the Sweet Solera Stakes on Newmarket's July course last August.
An injury soon after curtailed her season, but Al Zarooni has been pleased with her preparations - even though he believes she will be more effective over a longer trip.
"She had a knee problem. It was not a big injury but because she is a nice filly we decided to sit back with her and leave her for this year," he said.
"I think she's a mile-and-a-half filly. For me, she is more of an Oaks filly than a Guineas filly.
"But we're going to run her in the Guineas and she showed a good turn of foot when winning her Group Three well.
"We have never tried her on ground on the soft side, but I think she will go on it."
