Djokovic says he 's motivated to try to break Federer 's mark .
Djokovic 's 10 career Grand Slam crowns puts him four behind Rafael Nadal and Pete Sampras and seven behind Federer on the all - time list .
Djokovic , whose 10 career Grand Slam crowns puts him four behind Rafael Nadal and Pete Sampras and seven behind Federer on the all - time list , says he 's motivated to try to break Federer 's mark .