Racing endured its own version of market meltdown yesterday when three high-profile horses were retired. However, if injuries to Phoenix Tower and the Kentucky Derby winner, Big Brown, were unforeseeable, Zarkava's procession to the paddocks was not unexpected.

The Aga Khan yesterday cited Zarkava's value to his broodmare band as the principal reason for retiring his unbeaten winner of the Prix de l'Arc de Triomphe. Zarkava's next date will be a tryst with Dalakhani. “While no-one will regret more than my management team and I not to see Zarkava race again,” the Aga Khan said in a statement, “we have decided to retire her to the broodmare band as she will be an invaluable asset to this essential part of our activity.

“The quality and youth of our broodmare band is of the utmost importance to ensure we remain breeders of racehorses capable of performing at the top level."

Zarkava's fate will dismay fans of a filly who retires untested in seven races under the care of Alain de Royer-Dupré. “She is possibly the best I have trained,” the French trainer said, “but Dalakhani was also a great horse.”

Although Zarkava's finest hour arrived in the Arc, the filly also retires as a dual classic winner. In addition to her French 1000 Guineas and French Oaks victories, she also claimed the Prix Marcel Boussac as a two-year-old and the Prix Vermeille in September.

Phoenix Tower sustained a tendon injury that rules him out of Saturday's Emirates Champion Stakes - for which New Approach heads a maximum cast of 12.

Big Brown's retirement, after he ripped a hoof to shreds during a workout, deprives the Breeders' Cup Classic of his much-anticipated showdown with Curlin, last year's Horse of the Year in America. Curlin is expected to face a strong European challenge at Santa Anita on Saturday week.