Ante-post favourite Al Riffa will not run in in Saturday’s Irish 2,000 Guineas after suffering “a little setback” in training.

A son of Wootton Bassett, he made three starts last year for Joseph O’Brien, all at the Curragh, and signed off the campaign with a length-and-a-quarter success over Proud And Regal in the Group One National Stakes.

However, the Jassim Bin Al Attiyah-owned colt has not raced since September and while market leader for the mile Classic, he will be a notable absentee.

O’Brien said: “He has just had a little setback training. Hopefully it is nothing too serious and he will be back later in the summer.

“He has options at Ascot and further afield than that as well.

“These things happen, so it’s a long way from a problem. It is obviously disappointing for the owners. This race has been his target for the last while, but we will look forward to things later in the summer.

“Timing-wise Royal Ascot will be fine, but we will have to decide whether we want to run there or in other races. We’ll not be rushing into any decision.

“Everything else is good. We are looking forward to what is going to be a great weekend of racing at the Curragh. It is very competitive action and there’s much to look forward to.”

With Al Riffa missing the race, Qipco 2000 Guineas winner Chaldean heads the market.