Hiring Andy Murray as his coach came naturally for Novak Djokovic. On a trip to Argentina to play in a farewell match for Juan Martin del Potro, the Serbian explained why he chose his former rival after being without a coach for six months.

Murray and Djokovic announced last week they plan to work together for the Australian Open in January. “Since I was very young, I have played against him, and there are not many people who have won multiple Grand Slam titles,” said Djokovic in Spanish in a press conference before the match against Del Potro.