Aidan O’Brien is expecting to see improvement from his exciting juvenile Sergei Diaghilev in next week’s Listed Windsor Castle Stakes (1000m).

The master of Ballydoyle plundered the prize with the well-backed Little Big Bear in 2022, and his latest contender Sergei Diaghilev will head into the contest having won the same maiden at the Curragh that subsequent Group 1 scorers Unquestionable and Henri Matisse, as well as the talented Brussels, have landed in recent years.

The son of Wootton Bassett is bred to stay further being a brother to fellow Royal Ascot contender Endorsement, but O’Brien is happy this is the right spot for his once-raced juvenile.

He told At The Races in a recent stable tour: “He’ll be the one for the Windsor Castle Stakes. He’ll stay at least seven furlongs, but we think he has improved since his debut, and this looks a good spot for him.”

Robson De Aguiar has become well-renowned for his juvenile performers and Controlla could provide the Mullingarp-based handler with his best chance of the week.

The Amo Racing-owned daughter of Night Of Thunder couldn’t have gone much closer to making the perfect winning debut in the Group 3 Coolmore Stud Irish EBF Fillies Sprint Stakes (1200m) when denied a neck by Victorious, who is now two from two and well-fancied for the Group 2 Queen Mary Stakes (1000m), and she adds further depth to a strong Irish challenge.

The home team may well be led by impressive first-time-out Newbury winner Aperoll, although Richard Hannon’s charge still holds an entry in the Listed Chesham Stakes (1400m) later in the week, while Hugo Palmer’s equally taking debut scorer Sale Shark couldn’t be ruled out and the more experienced Say Squirrel, runner-up in Listed company at Vichy, looks set to represent France.

Photo: Focus On Racing