Aidan O'Brien will test the water on the Knavesmire at York ahead of tomorrow's crucial Dante Stakes showdown when Together Forever tackles today's Musidora Stakes.
The Ballydoyle maestro has declared both John F Kennedy and Ol' Man River for the day-two showpiece. Ryan Moore has opted to stick with the Ballysax flop John F Kennedy and the trainer's son Joseph is likewise reunited with Ol' Man River, which trailed in last in the 2,000 Guineas.
It promises to be a deeply informative edition of the 10-furlong Group Two, as John Gosden's Jack Hobbs and Andre Balding's Elm Park are also among the eight declarations.
They are the only two that precede John F Kennedy in the ante-post Derby betting, so tomorrow's clash promises to have significant ramifications after what has hitherto been a confusing few weeks of trials. Gosden also has the capacity to prove a thorn in Ballydoyle's side in today's Group Three.
Just five have been declared for the fillies' contest over the Dante course and distance, and the exceptional Newmarket handler's Star Of Seville looks to be the main threat to the Moore-ridden Together Forever.
A facile Doncaster maiden winner on her second start in October, the Duke Of Marmalade filly scored with a touch of style over this trip on her Newbury reappearance.
Winters Moon finished seven lengths back on that occasion, and it's worth noting that she got to within half-a-length of Together Forever when third in the Fillies' Mile at Newmarket in October. She has since finished seven lengths behind Jazzi Top on Guineas weekend, so the form looks pretty solid.
If, as is quite likely, Star Of Seville comes on a little for last month's outing, she could topple Together Forever under the rejuvenated Frankie Dettori.
Together Forever progressed really well throughout last season, so the fear with her would be that she might need today's run to put her right.
Fourth to the 1,000 Guineas winner Legatissimo on her Galway debut before finishing second to Found at the Curragh and then third to Jack Naylor and Legatissimo in a Curragh Listed race, she dispensed readily with the useful Rivers Of Babylon to finally break her duck at Gowran Park in September.
Together Forever went on from there to again win tidily in Listed company before grinding out her Group One triumph at Newmarket, when the Guineas runner-up Lucida was among her victims.
The daughter of Galileo clearly has plenty ability, but the suspicion is that she will be more vulnerable today than she might be in future.
Eddie Lynam is responsible for the only other Irish-trained runners at York this afternoon, Balmont Mast and Gathering Power charged with reinforcing the view of the excellent Co Meath handler as an exemplary trainer of sprinters.
Gathering Power has a lot on her plate at the ratings in the Clipper Logistics Stakes that was memorably won by Evanna McCutcheon's Maarek last year. Kieren Fallon's mount is the lowest rated of the 15 runners in the Group Two on a mark of 102, so this will be tough for her.
Preferred in that is Naadirr. Marco Botti's four-year-old beat the re-opposing Astaire when last seen at Doncaster in March, form that was franked by Astaire going on to win at Newmarket.
Off three-pound better terms now, Naadirr has plenty going for him from a favourably high draw under Letterkenny-born Martin Harley.
A high draw of 19 might help the cause of Lynam's Balmont Mast in the six-furlong handicap. The seven-year-old hasn't won since landing a Curragh Listed race in 2013, but he has been pretty consistent in good company.
On his latest outing at Naas two weeks ago, he kept on gamely to be fifth under a mammoth 10st 2lb for a mark of 101. Balmont Mast drops a pound here and gets in off 9st 3lb under Adam Kirby, so he is fancied to go close in what is a wide-open contest.
Of the raiders at Perth, Gordon Elliott's The Absent Mare gets the nod in a pretty weak novices' handicap chase.
Third at Wexford before finishing fifth over hurdles in the north last week, Richard Johnson's mount rarely runs a bad race.