Novak Djokovic could be on a collision course with Roger Federer after he suggested that Davis Cup and ATP Cup must be merged and moved to September - the same month as Federer's brainchild, Laver Cup. 

The revamped Davis Cup, which is underway in Madrid will be followed by the ATP Cup next year in January in Australia. Meanwhile, the Laver Cup – a Europe vs Rest of the World event is organized by Roger Federer's management team and was only introduced last year.

Djokovic has insisted that two world cup-style events - Davis Cup and ATP Cup - starting six weeks apart does not make any sense and has called out to the International Tennis Federation (ITF) and Association of Tennis Professionals (ATP) to come together and form a single team competition.

Djokovic currently is representing Serbia in the revamped Davis Cup and after beating Japan's Yoshihito Nishioka, he said, "Scheduling was always an issue for both the ATP Cup and Davis Cup. An idea – that could happen – was to merge the two. I think it’s still open for the future. Looking long-term, I don’t think that the two events can coexist six weeks apart. It’s just a bit too congested."

"I’ve been part of discussions through the player council, in various ways in the last three years, about the evolution of the ATP Cup and the changes in Davis Cup. And, of course, the ITF and ATP are two different organizations. So it’s very complex. It’s not easy to make any change in our sport. But, when the change is made, at least you make that first step. Of course, you can always point out the negatives but there are positives as well."

Insisting that it's never an easy task to reschedule a tournament keeping in mind "so many different tournaments that may get hampered," Djokovic suggested the month of September for the merged version of Davis Cup and ATP Cup.

"The most ideal time of the year is after the US Open, probably the end of September. That would be the best time to have this super cup, whatever, one cup hopefully in the future. That’s my opinion. I don’t know whether that’s realistic or not, whether that’s possible. There are so many different things, so many different people and entities involved that it’s not easy just to say, ‘Let’s pick that date,’ because you have so many different tournaments that you are harming maybe because of that week and so forth," the 16-time Grand Slam winner added.