Aidan O’Brien’s Arc team narrows to three, with Diamond Necklace still uncertain

Aidan O’Brien intends to run three horses in Sunday’s Prix de l’Arc de Triomphe after his team narrowed at Monday’s confirmation stage. Minnie Hauk, Diamond Necklace and Benvenuto Cellini remain in his plans for the 4 October race at ParisLongchamp. Diamond Necklace’s place is still uncertain: O’Brien said he would assess the ground closer to the weekend before making a final decision.

Sporting Life reported that five other Ballydoyle horses were removed at the confirmation stage: Jan Brueghel, Hawk Mountain, Montreal, Pierre Bonnard and Constitution River. That left O’Brien with three possible runners as the field took shape, rather than three confirmed starters. Another confirmation stage is scheduled for Wednesday, and the final field and draw are due Thursday, according to the racing outlet.

Diamond Necklace’s decision depends on the course

At a press conference reported by race organiser France Galop, O’Brien said the intention was to run all three horses. Diamond Necklace, however, also has the Prix de l’Opéra on the same day as an option. O’Brien said that alternative was not his preferred plan at the time, while leaving the final choice open until he could judge conditions nearer the race.

The Arc would be Diamond Necklace’s first race over 2,400 metres. O’Brien said he would prefer good going for that attempt and could not be certain in advance that she would stay the distance. Those questions give the course assessment practical importance: the trainer has named an intended runner, but has also explained why her participation cannot yet be treated as settled.

Minnie Hauk and Benvenuto Cellini

Minnie Hauk brings recent Arc experience to the prospective team. She finished second to Daryz in the 2025 race, according to France Galop, and returns this year as a four-year-old. Diamond Necklace and Benvenuto Cellini are both three. France Galop reported that foot problems had affected Minnie Hauk during the year; O’Brien said the Arc had remained her end-of-season target and that he was pleased with her latest run.

Benvenuto Cellini won the Irish Derby but finished fifth in the Prix Niel, a preparatory race. O’Brien said the Niel was run slowly after the field did not follow the pacemaker, which he thought partly explained the placing. He said a steadily run 2,400-metre race would suit the colt. That is the trainer’s assessment of what Benvenuto Cellini needs, rather than a prediction of how the Arc will unfold.

O’Brien told the France Galop press conference that he would like good going for all three of his possible runners. He said jockey arrangements would depend on Ryan Moore’s choice. Both points remain part of the planning for Sunday: the named horses are the stable’s current candidates, while the conditions and riding arrangements have yet to be resolved.

A field still taking shape

The wider field is also provisional. Sporting Life reported that Joseph O’Brien’s Thundering On remained in contention. Friendly Soul could be added after winning the Prix Vermeille, with a decision on taking up the available supplementary entry due Wednesday. Those possibilities sit alongside the next confirmation stage, so Monday’s list should not be read as the final line-up.

France Galop says Aidan O’Brien had saddled 58 Arc runners since his first in 1999 before this year’s edition. He has won twice, with Dylan Thomas in 2007 and Found in 2016. Minnie Hauk’s second place last year adds a recent result to that record, but it does not settle which of his horses will start this Sunday or how they will fare.

The next decisions will clarify the race rather than change what O’Brien said on Monday: whether Diamond Necklace goes to the Arc or the Prix de l’Opéra, whether Friendly Soul is supplemented, and which horses remain after Wednesday’s confirmation. Sporting Life said the final field and draw are due Thursday. Until then, O’Brien’s three-horse plan remains an intention, with one runner’s route expressly dependent on a later decision.