O'Brien reports Septimus to be in good shape ahead of today's Dante Stakes at York where the Ballydoyle team will try to continue their recent hot streak.
Despite Alexandrova being beaten in yesterday's Musidora, O'Brien declared himself satisfied with her run and she remains a likely starter in the Epsom Oaks if the ground is suitable.
Septimus himself is as low as 12 to 1 for the Derby despite finishing only seventh of nine on his first start of the season in France last month.
"We think he has come on a good bit for that and we're very happy with him," the champion trainer said yesterday. "The ground didn't seem too bad at York yesterday so he should be okay on it."
Horatio Nelson and the Derrinstown winner Dylan Thomas have already been earmarked as likely Derby starters at Epsom for O'Brien, whose hand could get even stronger with a good run by Septimus today.
O'Brien enjoyed Guineas success at Longchamp on Sunday and he hasn't ruled out returning to the Paris track this weekend in an attempt to secure a winning Group One bracket for Ace in the Prix d'Ispahan.
Last year's Breeders' Cup runner up has been placed in five of his nine starts at Group One level to date.
"It's possible he could go but he does have other alternatives like the Tattersalls and the Coronation Cup," said O'Brien, who is also mulling over the possibility of running the Gowran winner Poseidon Adventure in Sunday's Italian Derby.
John Oxx has all but ruled out King In Waiting from a tilt at the Epsom Derby and instead the colt will be held in reserve for a possible attempt at the Irish Derby later next month.
King In Waiting won his sole start to date at the Curragh in March but has had his progress since interrupted by a series of minor setbacks, the last of which ruled him out of last weekend's Derrinstown Stud Derby Trial.
"He got a little pulled muscle in his quarters a few days before the race," Oxx explained yesterday. "He looked a nice horse the first day, and we do like him, but I would say he is unlikely to be left in the Derby. Instead I would hope to run him on Sunday week at the Curragh in the Gallinule Stakes and see if he is good enough for the Irish Derby."
Also on Irish 1,000 Guineas day, Oxx hopes to run his smart four-year-old Alayan against big international guns like Hurricane Run in the Tattersalls Gold Cup.
If Tipperary's rejigged all National Hunt card survives the wet weather this evening it will be good news for the champion jockey Ruby Walsh who looks to have good prospects of landing the first two races.
Josephine Cullen has to concede weight in the opener but is in the sort of form, after following up a good Limerick run with a win at Punchestown, that suggests it shouldn't be a problem.
Walsh is an eye-catching booking for the Robert Tyner-trained Askthemaster in the first division of the maiden hurdle and this course bumper winner can score again while Line Ball's third last Christmas to Finger On the Pulse would be good enough to land the second division.
Joan's Girl won over two miles on the course last month and the half mile further in the first part of the amateur handicap hurdle should not be a problem for Francis Flood's horse.