Djokovic eyeing third US Open title but his 'serve is still a work in progress'

Novak Djokovic heads into the US Open in sizzling form after collecting a fourth Wimbledon title and completing a sweep of Masters series events over the last month, but the Serb admits there were times when the long road back from injury brought "more than a few moments of doubt" about his future.

An elbow injury forced Djokovic to retire against Czech Tomas Berdych in the quarter-finals of Wimbledon in 2017. After that came a series of early tournament exits and, finally, surgery.

"I think one of the biggest things I’ve learned about myself is how impatient I was," the 13-time Grand Slam winner told reporters on Wednesday, reflecting on his recovery process.

"That was probably one of the hardest ways for me to learn to be patient.

"I’ve never faced any major injury in my career -- (for) which I was very fortunate," Djokovic added.

"But I guess even with the care that I had the body took a lot of beating and eventually I had to address the elbow injury more seriously."

With the world's best players descending on Flushing, Queens next week, Djokovic is aiming to add a third US Open title to his name -- and to perfect his serve.

"It’s still a work in progress with the serve, to be honest," Djokovic said.

"I’m aware that I can’t serve as the guys who are 6’10” obviously can. I’m not looking for that speed – I’m looking more for precision and accuracy."

Even so, the 6'2" (1.88m) Serbian said his serve worked well for him against 6'8" South African Kevin Anderson, whom he beat this year to clinch his fourth Wimbledon men's singles title, ending his two-year Grand Slam drought.

He defeated Roger Federer on Sunday in the Cincinnati Masters final, becoming the first player to complete a sweep of Masters series tournaments.

That kind of success would be thrilling under any circumstances but Djokovic said the hard road back made it even more satisfying.

 “The Wimbledon win and the Cincinnati win now are much sweeter, more special," Djokovic said, "because of the journey.”