Former world number one Novak Djokovic feels a sharp upturn in form could be just around the corner following his reunion with long-term coach Marian Vajda.

A persistent elbow problem forced Djokovic to end his 2017 season prematurely after withdrawing from the quarter-finals of Wimbledon in July, and the Serbian now sits a relatively distant 12th in the rankings. 

He made a comeback at the Australian Open in January but then underwent minor surgery to address the same problem in February, returning to action the following month in Miami.

Djokovic parted ways with coaches Radek Stepanek and Andre Agassi earlier this month, bringing Vajda and fitness coach Gebhard Gritsch back into the fold.

The 30-year-old lost to Martin Klizan in his first match at the Barcelona Open in his most recent competitive appearance, and continues to struggle for consistency ahead of the French Open, which starts in Paris later this month.

However, speaking to reporters after a practice session in Belgrade on Wednesday, the 12-time grand slam singles champion offered an optimistic update on his progress. 

"I've been playing without pain on court since Miami and that is the best news at the moment, as I had really great problems playing without [experiencing] significant pain," he said.

"Basically, now it is all about elevating form. 

"Marian and GG are back in the team and I am very happy to have them alongside me, because they know me very well, know my game really well and me as a person. 

"I believe [the] pieces will somehow quickly fall into place and I hope for some better results already in the coming few weeks."

Prior to his swift Barcelona exit, Djokovic had reached the last 16 at the Monte Carlo Masters, losing to Dominic Thiem.

And he acknowledged the toll a lengthy battle for form and fitness has taken on what had previously appeared to be an iron-clad self-belief.  

"Given that I did not have the results I had over the past 10 years or so, it is normal that the level of [my] confidence is not the same," he said.

"It is lower than before, normally, than what I myself have become used to, which the people watching from the sides could also see. 

"But, let me say again, that can return very quickly. A few good matches are required, one good tournament."

Nevertheless, Djokovic remains determined to climb back up the rankings and emulate the likes of Rafael Nadal and Roger Federer by staging a late-career renaissance. 

He said: "I had to lower [my] expectations, simply because of the circumstances of the past 12 months, but the goals are more or less the same as they were throughout my professional career."