Sandra Harwitt

Special for USA TODAY Sports

WIMBLEDON, England — Last week, John McEnroe was making controversial statements about Serena Williams, suggesting that while she might be the best women’s player of all-time, she’d only be ranked No. 700 if she competed on the men’s tour.

Two night’s ago, while commentating for BBC TV, McEnroe decided to publicly discuss a possible reason why Novak Djokovic has struggled with his tennis since he failed to defend his Wimbledon title last year.

Last year, after losing to American Sam Querrey in the Wimbledon third round, Djokovic cited “private” issues.

During Tuesday’s broadcast, McEnroe said, ”(He’s) had some off-court issues with the family. That's going to throw you. If you're distracted you're not the same player.”

McEnroe then likened Djokovic, 30, to another famous athlete, golfer Tiger Woods, who went through a messy public marital breakup.

"The person that comes to mind immediately with Novak is not a tennis player, it's actually a golfer: Tiger Woods,” McEnroe said. “When he [Woods] had the issues with his wife, and then he seemed to go completely off the rails and has never been even close to being the same player. So we're starting to say: 'Wait a minute, is this possible with him [Djokovic]?'"

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The second-seeded Djokovic, who is expecting a second child with wife, Jelena, was polished in discussing McEnroe’s remarks after he posted an easy 6-2, 6-2, 6-1 victory against Adam Pavlasek of the Czech Republic on Thursday.

“Look, John has a complete right to say — anybody, really, in the world has a right to say what they want, and I respect that right,” he said. “Especially coming from John, because he’s someone that has earned that right because of who he is and what he has meant to the sport, and what he still is representing as a former player and still being very active on tour.

“And he’s very well known for his kind of bold comments and not really caring too much about being politically correct, but saying whatever is on his mind,” Djokovic added. “That’s all I can say. I really don’t take anything personal. I always got along very well with John. I guess whether that’s his opinion or criticism or something else, I’m not really sure.”

Only Djokovic and his family know what, if anything, could be responsible for his faltering career.

What is known is that until the 2016 edition of Wimbledon, Djokovic was the ace of men’s tennis. The Serbian, who started his love for tennis on a court surfaced inside a former swimming pool, emerged from a war-torn nation to become the No. 1 player in the world.

When Djokovic arrived in London last year, he did so with great confidence. He was just a few weeks from having become only the eighth player in history to own at least one trophy from all four of the Grand Slam tournaments. It had long been his quest to win a French Open title — he had been in three previous finals — but it wasn’t until 2016 that he finally fulfilled that dream.

To make the achievement of scoring a 12th career Grand Slam title even sweeter, the French Open victory provided Djokovic with a rare non-calendar Grand Slam — he’d won all four majors successively, by bridging the 2015-16 seasons.

Since that time, however, Djokovic's best Grand Slam result was reaching the 2016 U.S. Open final. In 2017, he was unsuccessful in defending his Australian Open and Roland Garros titles, losing in the second round and quarterfinals, respectively.

He’s currently ranked No. 4, but is seeded No. 2 in deference to his penchant for playing well on grass and his three past Wimbledon titles. Although Djokovic normally eschews playing the tuneup grass court events, he took a wildcard into Eastbourne last week and won his second title of the year.

Will a strong performance at Wimbledon this year quell whatever issues Djokovic has been facing the past 12 months?

“Even though, maybe, results haven’t been up to the standard that I have had in the last seven, eight years, in order to reach a new peak, you have to fold a little bit in some way,” Djokovic said, when asked how important it is for him to do well at Wimbledon. “I’m still very proud of what I’ve managed to achieve and accomplish.

“I’m not regretting anything,” he added. “I just am someone that believes everything in life happens for a reason. So I find myself in this situation where I just learn, evolve, and I try to get to another stage, to another level as a person and as a player.”