Duke On Course For Curragh Stan James 2000 Guineas fourth Duke Of Marmalade is likely to spearhead Aidan O´Brien´s challenge in Saturday´s Irish equivalent at the Curragh.The Ballydoyle maestro has seven possibles still engaged in the Boylesports-sponsored Classic following Monday´s confirmation stage.'Duke Of Marmalade is an intended runner at the Curragh and while Eagle Mountain might run, we still have the Prix du Jockey-Club as an option for him,' said O´Brien.'Plans for him are still up in the air and it will be a few days before we make a decision.'O´Brien´s other five possibles are Spanish Harlem, Trinity College, Japura, Excellent Art and Derrinstown Stud Derby Trial winner Archipenko.While running plans are yet to be firmed up, O´Brien says he could saddle a few in the upcoming Classic.'We might run a few, but nothing will be decided until later in the week,' he told the Racing Post.'Excellent Art is a possible. We´ll see how he is in a few days as it´s just over a week since he ran in France.'There is no real significance in Archipenko being left in Saturday´s race. The current plan is that he will go for the Epsom Derby.'(C) PA Sport