Serbia's player Novak Djokovic reacts during his match against Sam Querrey of the U.S. at the Paris Tennis Masters tournament, Wednesday, Oct. 31, 2012. Sam Querrey defeated Novak Djokovic. (AP Photo/Remy de la Mauviniere)

Photo by: Remy de la Mauviniere

Serbia's player Novak Djokovic reacts during his match against Sam Querrey of the U.S. at the Paris Tennis Masters tournament, Wednesday, Oct. 31, 2012. Sam Querrey defeated Novak Djokovic. (AP Photo/Remy de la Mauviniere)