Davy Fitzgerald has been admitted to hospital for tests related to a health concern.
The Clare hurling manager checked into a clinic in Galway last night and was transferred to a hospital in Dublin this morning.
It is still hoped that Fitzgerald will be at Clare's All-Ireland Hurling Championship quarter-final against Galway on Sunday.
However, if he is kept in hospital it is likely that Donal Og Cusack will take charge on the sidelines for the Banner county at Semple Stadium.
Fitzgerald has already had minor heart surgery in 2009 to have stents inserted due to a blocked artery.