Which jockey was barred from riding in the Derby in 2017?

The British Horse racing Authority (BHA) has the power to reject the declaration of a jockey in a Group One race if, for example, he or she fails to meet certain minimum criteria. In 2017, Diore Lia – an unfashionably bred filly, with no official rating after two, unplaced efforts in ordinary maiden races – was entered for the Derby by trainer John Jenkins. Understandably priced up as a 1,000/1 rank outsider, Diore Lia was due to be ridden by Jenkins’ apprentice Gina Mangan who, at the time, had ridden just a single winner, Salazaar, at Roscommon eight years earlier.

However, on the Wednesday before the Derby, the BHA intervened, barring Mangan from taking the ride on the grounds that she had yet to ride in a race ‘on the scale and stage of the Derby’. Richard Aylward, who bred Diore Lia and co-owns the filly with his sister, Mary Todd, initially said that the horse would be scratched, but changed his mind and, instead, replaced Mangan with more experienced apprentice Paddy Pilley. Unfortunately, Diore Lia was withdrawn on the morning of race, in any case, having suffered a muscle injury.