Aidan O'Brien believes factions of his huge team might not be firing on all cylinders.

The Ballydoyle handler is closely monitoring the well-being of his horses, and highlighted Magic Wand's disappointment in the Irish Oaks on Sunday - she was later found to have had a dirty nose - as a reason to adopt a cautious approach.

O'Brien said: "Our horses are just going through a little bit of a stage - a little bit of a change - and the odd one is not scoping right at the moment.

"We've seen it with the filly in the Oaks and we just have to be careful."