Novak Djokovic
Novak Djokovic looked impressive in his opening round win over Kei Nishikori in the Madrid Open. Pictured, Djokovic of Serbia celebrates to the crowd after his straight sets victory against Kei Nishikori of Japan in their first round match during day three of the Mutua Madrid Open tennis tournament at the Caja Magica in Madrid, Spain, May 7, 2018. Clive Brunskill/Getty Images

Juan Martin del Potro is hoping Novak Djokovic returns to his best as it will only benefit the tennis world.

Djokovic was dominating the sport from 2011 to 2016 as he won 11 of his 12 Grand Slam titles during that five-year spell. He also became just the third player to hold all four Grand Slam titles at the same time when he achieved the feat at the 2016 French Open.

However, 2017 saw a major fall in grace for the Serbian as he won just two ATP 250 titles with his best Grand Slam performances being quarterfinal exits at the French Open and Wimbledon in July.

A niggling elbow problem was a major factor as Djokovic would take time off after Wimbledon in a bid to recuperate as he later returned for the Australian Open in January.

The 30-year-old was promising in his comeback but exited in the round of 16 before suffering consecutive opening round defeats at the BNP Paribas Open and the Miami Open in March, though he finally underwent surgery on his elbow in February.

Despite further defeats in the Monte-Carlo Masters and the Barcelona Open last month, Del Potro, who experienced his fair share of injury problems, still believes Djokovic can return to old glories.

"I also had a couple of injuries in the past. It's not easy. It's not something nice to suffer," Del Potro said, as per Tennis.com. "It's not nice to see that you're falling down in the rankings, that you're not feeling as good as you're used to feeling, because he's always been really fit."

"There are few players that can come back from injuries and be so good, be up in the rankings where they deserve to be. Djokovic is one of those players. Also [Andy] Murray did it, [Stan] Wawrinka. There are not many more players that are capable of coming back from injury."

Despite his recent clay losses, a now pain-free Djokovic is continuing to build his fitness and confidence ahead of the French Open and took a major step at that when he had arguably his best win since the start of 2017 after defeating Kei Nishikori in his opening round match Monday in the Madrid Open.

A good run in Madrid and then the Italian Open before Roland Garros could help Djokovic experience a career resurgence, which is something Del Potro would like to see for his friend as it will make tennis even more interesting.

"For me personally, I would like to see Djokovic come back in the place where he should be," Del Potro added. "Hopefully, he'll be able to do that because I really like him, I really support him. ... It will not only be good for him but it will be good for the tennis world so that we can see again another great player, so we can see him fighting up there for Grand Slams, fighting for the No. 1 with all the top players. We have great players. That will make the tennis even more entertaining."

Djokovic takes on Australian Open semi-finalist Kyle Edmund next on Wednesday.