Swiss world number one Roger Federer (L) and Spanish world number two Rafael Nadal pose for pictures after playing an exhibition game on January 3, 2010 in the old center of the Qatari capital Doha, where they will be competing in the season-opening ATP tennis tournalment starting January 4. Tennis'' two greatest heroes are scheduled to play the Qatar Open as they bid to lift the trophy won last year by Scot Andy Murray.