New York: Marriage and preparations for the birth of his first child left Novak Djokovic "a little flat" on the tennis court of late — where better to turn things around than at the US Open.

Novak Djokovic and Jelena Ristic
Novak Djokovic and Jelena Ristic 

Djokovic, the 2011 US Open champion who captured a seventh Grand Slam crown at Wimbledon in July, was still celebrating that title when he married longtime girlfriend Jelena Ristic, and the couple are expecting their first child in less than two months.

Djokovic said: "Priorities change. My priorities — my family, my wife, my future kid — tennis is definitely not number one anymore."

If Djokovic wants a current example of a player who makes parenthood on the pro tennis circuit work, he need look no further than Roger Federer.

Roger should know
Federer, father of two sets of twins, is enjoying a career resurgence that has many tipping him to be lifting an 18th Grand Slam trophy in two weeks.

Federer said he didn't know if he had any specific advice to offer Djokovic, except to enjoy it all. "I think he must be quite excited about what's going to happen soon," Federer said. "And with the wedding and everything – he's going through a great spell at the moment, with winning Wimbledon on top of it.

But I think he's got to figure it out himself really. But the good thing, he sees me with four (children), so with one it should be a piece of cake."

Overall Djokovic believes happiness in his personal life can translate into better tennis, even as family gains importance.

"Especially at this stage of my career, where I feel like now is the time that I'm at my peak physical strength, I want to use this time of my career as much as I can to win as many matches as possible," he said.