The former WTA No. 1 announced that she was hanging up her racquet in a video message a week ago, saying physical and motivational issues meant she could not compete at the highest level. Djokovic and Ivanovic played together as kids in junior events in Serbia, and came up together on the pro circuit. In 2008, they became the first Serbs to win Grand Slam singles titles.
"I was very emotional when I watched it, simply because I've known Ana since we were five years old," he said. "We go back a long time. We're friends, colleagues. You know, we've shared many moments together on the tour—in the junior circuit in Serbia, internationally. We've grown up together and our families have known each other.
"It was a really touching moment to see that happen, and I can imagine how hard it was for her to make that step and decision, and just decide to stop playing tennis."
Djokovic noted that the recently-married Ivanovic certainly weighed her decision carefully.
"You know, I'm sure that she has done it with the right frame of mind, and the right emotion,” the world No. 2 said. “At least she seems like that."
"I think she was thinking a lot,” Angelique Kerber, a good friend of Ivanovic’s added. “And I think, for her, that's her decision."
Ivanovic won 15 titles during her 13-year career.