How Novak Djokovic's persona has changed throughout the years

The last time we saw Novak Djokovic enter the All England Club, he was riding a rare wave in tennis. He had just completed the career Slam after beating Andy Murray in the French Open final and entered Wimbledon as the player to beat. But then, an unexpected third-round loss against American Sam Querrey (his earliest exit in a Slam since 2009 at Roland Garros) began a yearlong slide that he has yet to recover from. He has often looked tormented on the court and has questioned his play openly to the media.

That's the Djokovic we have seen of late heading into this year's Wimbledon tournament.

In his 13 years on tour, Djokovic has regularly been one of the biggest and most polarizing personalities on tour. But it's a persona that has seen many phases over the years.

Early years: Prosperous but plagued

Djokovic was considered a future star from the time he started on the junior circuit. Although he never won a major, he was 40-11 in his three-plus-year stint (2001-04) and seemed ready to compete on the men's tour. But Djokovic was overcome with physical woes on a regular basis, and experts wondered if he would have the stamina to compete over a two-week stretch of a major.

Djokovic regularly retired from matches -- seven total in his first three seasons on tour, nearly twice as many as he has had since. Some speculated his issues were a result of asthma, while others assumed he didn't train hard enough. Djokovic went so far as undergoing nasal surgery and also taking up yoga. Nothing worked.

The images of Djokovic slumped over in his chair, trying to figure out what was going on seem like a distant memory now, but they were real.

Rock star in the making

In 2008, Djokovic finally lifted the hardware he had longed for his entire life. With a four-set win against Jo-Wilfried Tsonga in the Australian Open final, Djokovic cemented himself as a top-tier player. At the time, while a major prospect, he was still relatively unknown outside tennis circles. His country had never seen a player rise to such heights, and they were ready to let Djokovic hear about it.

"I think it's a crazy house back in Serbia right now," Djokovic said to the media afterward. The entire aura of Djokovic had changed. He wasn't just a champion, but a king back home.

While Serbia was in a craze, the Aussie Open crowd clearly rooted for Tsonga, but as Djokovic said afterward, it was his ability to fight off the crowd, as well as his opponent, that ultimately led to his first major win.

The villain

There was tension between Djokovic and American Andy Roddick long before they struck one ball in their quarterfinal-round match at the 2008 US Open.

Roddick, had suggested earlier in the tournament match that Djokovic regularly feigned injury, and joked that "we might as well add bird flu, SARS and anthrax" to the list of Djokovic's ailments.

Djokovic did call the trainer several times in his previous match, a five-set battle in which the Serb suffered from hip, ankle, stomach and breathing problems. "He's either quick to call a trainer, or he's the most courageous guy of all time," Roddick told reporters.

The remarks motivated Djokovic, who ended Roddick's run in four sets; but it was Djoker's postmatch on-court comments that sparked a change in how fans perceived him.

"You know, Andy was saying I have 16 injuries in the last match ... obviously, I don't -- right?" Djokovic said to a chorus of jeers from the charged night-match crowd. "They are already against me because they think I'm faking everything. That was not nice to say ... I have 16 injuries and I'm faking it. The momentum is not nice."

The health nut

Fed up with the physical setbacks that plagued a good part of his career, Djokovic gave up bread, pasta and, yes, his beloved pizza.

He switched to a gluten-free diet in 2011, and it worked. "I had to learn to listen to my body," Djokovic wrote in his book "Serve To Win."

"Once I did, everything changed. You could call it magic. It felt like magic." And he played like magic. Gone were the days when his body would give out for no apparent reason or fans would boo him for taking timeouts.

Djokovic changed trainers, workouts and coaches, but the ultimate culprit to his health struggle was a plate of spaghetti.

The change in diet had a direct effect on his results. Three years after winning his first major, at the 2008 Australian Open, Djokovic won a second Down Under, and from there, he won everything in sight.

In 2011, he reeled off 41 straight matches to start the season, a streak that lasted until June. He went 10-1 against Roger Federer and Rafael Nadal that year and also bagged three majors and five Masters titles. That was just the beginning. From 2011 to '16, Djokovic won 11 of 24 Grand Slam events and finished No. 1 in the world every year except 2013.

In a short period of time, he passed one Hall of Famer after another on the Grand Slam list, and as it stands, he is tied with Roy Emerson for fourth-most all time.

The impersonator

With more on-court success, Djokovic seemed to become more relaxed on the court after matches.

With his impersonations of fellow players (among those imitated were John McEnroe, Rafael Nadal, Serena Williams, Pat Cash and future coach Boris Becker) and postmatch dances, Djoker had become tennis' de facto king of comedy.

One of the most famous stunts was when Djokovic channeled his inner Maria Sharapova. The more Djokovic put on this impersonation act, the more fans wanted.

The struggling star

Djokovic won the French Open in June 2016 to complete his set of Grand Slam titles, but little did he know how much he'd unravel.

Djokovic had few answers as he struggled at Wimbledon and the Olympics, before falling to Murray in the final of the year-end championships to officially cede his No. 1 ranking. Rumors of personal issues went viral as well, something Djokovic spoke about in vague terms.

Shortly afterward, Djokovic split with coach Boris Becker before firing the rest of his staff in early May this season. Djokovic was left with guru-like mentor Pepe Imaz, who runs a tennis center in Marbella, Spain. But Imaz's focus is on a person's well-being, feelings and emotions.

How that translates into better forehands and backhands is unknown, but Djokovic seemed to enjoy the spiritual side of his existence, even if his game was not showing any improvement.

Before the start of the French Open, Djokovic also hired eight-time Grand Slam winner Andre Agassi on an a la carte basis to try to guide the Serb back to his winning ways. But at Roland Garros, Djokovic was crushed by Dominic Thiem in straight sets in the quarterfinals.

Now it's off to Wimbledon, where Djokovic hopes a fourth title is only a little more than two weeks away.