River Tiber out of Juvenile Turf

Unquestionable leads Aidan O’Brien’s search for back-to-back victories in the Breeders’ Cup Juvenile Turf at Santa Anita with ante-post favourite River Tiber scratched on the morning of the race.

The one-mile contest brings the opening night of Breeders’ Cup action to a close, with the Ballydoyle handler winning the race for a record-extending fifth time with Victoria Road at Keeneland 12 months ago.

Joining Unquestionable in O’Brien’ quest for victory number six, is Dundalk Listed winner Mountain Bear who will also face the starter in California.

The former is yet to get his head in front in Group company, but arrives on the American west coast on the back of a commendable effort when finishing an honourable second to Rosallion in the Prix Jean-Luc Lagardere at ParisLongchamp.

Speaking during Breakfast at the Breeders’ Cup on Thursday, O’Brien said of Unquestionable: “Ryan was delighted with him in France and said the split just came a little bit too early for him and he had to go early.

“Obviously when the split came he had to go and he would have just preferred to wait a little bit longer. He ran a very good race.

“We always felt a mile would be well within his compass and he’s in very good form and has a nice draw as well.”

The O’Brien duo are the sole European representation in a race the raiders have dominated since its inception, but there is a strong cast of American challengers lining up to take their chance.

Todd Pletcher struck in 2010 and will saddle the hat-trick-seeking Agate Road, while Michael McCarthy’s Endlessly is unbeaten in three and has track-and-trip form to his name.

Christophe Clement’s Carson’s Run accounted for My Boy Prince in the Grade One Summer Stakes at Woodbine, while the latter is joined by Can Group from Hall Of Fame handler Mark Casse’s well-respected stable.