BIRMINGHAM, England - Former Manchester United captain Roy Keane has quit as Aston Villa's assistant manager, saying he was finding it too hard to combine the position with his role in Ireland's coaching staff.

Keane says in a Villa statement that "it isn't fair to either Villa or Ireland, so I've made this decision."

The 43-year-old Keane joined Villa in July, after being hired as assistant to Ireland coach Martin O'Neill last November.

Villa manager Paul Lambert says "Roy came to me this morning and he informed me that, ultimately, the difficulty of combining both roles has prompted his decision, which I respect totally."

Villa is in 16th place in the 20-team Premier League.