Juan Martin Del Potro is confident he can challenge for Grand Slam titles next season after pushing Novak Djokovic all the way in the semi-finals of the ATP Tour Finals.
Juan Martin del Potro confident of challenge for Grand Slams in 2013
Juan Martin Del Potro is confident he can challenge for Grand Slam titles next season after pushing Novak Djokovic all the way in the semi-finals of the ATP Tour Finals.