John Isner, Gael Monfils withdraw from Heineken Open

Defending champion John Isner has withdrawn from next week's Heinken Tennis Open in Auckland citing tiredness.

Frenchman Gael Monfils has also withdrawn from the tournament at late notice for personal reasons.

Isner is currently partnering Serena Williams as the United States team at the Hopman Cup mixed teams event in Perth and will play in Saturday's final after playing 13 sets in leadup matches. He was a late replacement for Jack Sock.

Auckland tournament director Karl Budge said he was aware Monfils was dealing with personal issues and accepted his late withdrawal. But he said ''the situation around Isner is tougher to accept, for sure.''

Budge offered Rafael Nadal a wildcard after his loss in the first round of the Qatar Open but he declined.