Djokovic's serve showing signs of improvement at Australian Open

Novak Djokovic spent a lot of the offseason improving his serving, and it's showing at the Australian Open.

The No. 2 seed hit 17 aces during a third-round win against Yoshihito Nishioka that he described as one of the top serving performances of his career.

During a courtside interview, Djokovic jokingly said it was because his coach Goran Ivanisevic, who possessed one of the game's most legendary deliveries, has just arrived at the tournament.

But there is more to it than that -- the Serb had also noted in press that his serving was "something that I've worked on in the offseason" and still "one of the priorities" during the event.

Asked courtside what he had done, Djokovic smiled.

"You just hit more aces, I guess," he joked, before adding, "Easier said than done, obviously... There are a lot of technical details you can talk about but sometimes, less is more. We try to focus on [a] few simple kind of indicators.

"It's all about rhythm, it's all about balance, really, to find where is the contact point."

Djokovic also credited the expertise of Ivanisevic, who joined longtime coach Marian Vajda during the grasscourt season, and said he enjoyed having him on his team.

"Lots of fun, lots of joking around, we speak the same language. He was one of my childhood idols," he said.

Djokovic, a seven-time Australian Open champion, will get to assess his serving against one of the tour's best returners next when he meets Schwartzman in the fourth round.

The Serb got broken four times in the first round but has otherwise sailed through the first week at Melbourne.