MELBOURNE, Australia — And then there was one: The Big Three is down to just Novak Djokovic, who stands alone from a golden generation of men’s tennis now that Rafael Nadal has joined Roger Federer in retirement.

Novak Djokovic is opening up about his relationship with fellow tennis stars Roger Federer and Rafael Nadal, admitting that it's often strained.

The Serbian champion talked about his relationship with the Swiss and the Spaniard, in a long interview for GQ