Last year's Gold Cup runner-up Sir Des Champs has been ruled out for the season, his trainer Willie Mullins confirmed yesterday.
On the same afternoon that Eddie O'Leary confirmed Bryan Cooper will become Gigginstown House Stud's retained rider from Monday, Mullins revealed that Gigginstown's leading stayer Sir Des Champs – who was fourth in last week's Lexus Chase at Leopardstown – would have to miss the rest of the season due to a tendon injury.
The dual Cheltenham Festival winner was second behind Bobs Worth in the Gold Cup at Prestbury Park last March and after falling at just the third fence on his seasonal comeback in the John Durkan, he then finished fourth behind Bobs Worth last week at Leopardstown.
However, it was confirmed yesterday by Mullins that he had suffered a tendon injury and now with a similar injury to Flemenstar, he will miss the season.
"He has suffered slight damage to a tendon," said Mullins.
"The injury is going to take time to heal so we have decided to pull the plug on the remainder of the season."
Cooper's role as number one jockey to the leading owner will begin on Monday after O'Leary confirmed the appointment yesterday afternoon.
Cooper had effectively rode as second jockey to Russell when he wasn't tied up with commitments to Dessie Hughes and that arrangement saw him come in for the ride on First Lieutenant in the Betfred Bowl at Aintree when Russell was unable to pass the BHA doctor.
The 21-year-old was also on-board Roi Du Mee when he won the Grade One JNWine.com Champion Chase at Down Royal in November when Russell opted to ride First Lieutenant who finished fourth.
Eddie O'Leary, who is racing manager at his brother Michael's Gigginstown House Stud operation, said yesterday: "I can confirm that Bryan Cooper will be our number one retainer. He's a very good rider and I hope it will be the start of a long and happy association."
The Kerry native will have an unrestricted first call on all of the Gigginstown runners, with rumours that Ruby Walsh would ride those trained by Mullins quashed by O'Leary.
Walsh rides Mozoltov for Mullins and Gigginstown tomorrow in the novice chase at Naas as the announcement came after the declarations for tomorrow's card, with Cooper booked to ride the Tom Foley-trained Golanbrook in the same race.
Davy Russell is still expected to be used on a regular basis by Gigginstown when they have multiple runners in races in a similar role that Cooper was employed up until this week.
Dessie Hughes spoke on New Year's Day of his disappointment at losing Cooper who he had "matured" over the last four years.
He oversaw the youngster in his champion conditional campaign of two seasons ago.