Aston Villa have announced the shock resignation of manager Martin O'Neill with immediate effect.
O'Neill was seemingly preparing for this weekend's Premier League opener at home to West Ham but a statement from Villa this afternoon announced his departure, though no reason has been given.
"Aston Villa can confirm that Martin O'Neill has resigned as manager of the football club with immediate effect," said the statement. "Kevin MacDonald, reserve team manager, has assumed the role of caretaker manager and will prepare the team for the opening Barclays Premier League game of the season against West Ham on Saturday at Villa Park."
O'Neill said: "I have enjoyed my time at Aston Villa immensely.
"It's obviously a wrench to be leaving such a magnificent club.
"I would like to pay tribute to the Villa players, my coaching staff and the Villa supporters for all the support and encouragement they have given both the club and me personally during my time as manager.
"I wish them all the best for the future. I will obviously be assisting the club in the immediate short-term with regard to the handover of my duties."