The physical transformation of Novak Djokovic which caught the tennis world off guard

Roger Feder and Rafael Nadal had world tennis at their mercy so it seemed, but what they failed to see was a runaway ball of muscle growing larger in their rearview mirror.

It’s one of the great tennis trivia questions: What did Ivan Dodig do which made him stand out at the 2011 Australian Open?

The Croatian had the honour of being the only player to take a set off Novak Djokovic at Melbourne Park that year.

It was in the second round and Dodig won the second set tie-break 10-8. It was a brief moment of triumph as he then got wiped 6-0 6-2 in the remaining two sets.

A decade on and Dodig, 36, is back at the Australian Open playing in the doubles where he is a former Grand Slam champion having tasted success at Roland Garros in 2015.

Little did he know or anyone else realise that he was to play a role in a tennis revolution which has shaped history forever.

Djokovic had only won one grand slam title — the Australian Open in 2008 — when arrived at Melbourne Park a decade ago.

Swiss ace Roger Federer was miles out in front with 16 major titles while Spain‘s Rafael Nadal was leading the chase with nine.

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Serbia's Novak Djokovic overhauled his off-court set-up to dramatically change his physique.

The Serbian was recognised as a potential challenger to the pair but had struggled to shake the one-Slam wonder tag.

Numerous mid-match retirements and a lack of dedication were seen as the major stumbling blocks for the undoubted talent.

The other problem was the fact the gap was widening.

At the end of the 2010 season, only one of the previous 22 Grand Slam finals didn‘t include at least one of Federer or Nadal.

But in the lead-up to the 2011 Australian Open a transformation had taken place.

Djokovic had overhauled his off-court set-up including changing his diet dramatically to go vegan along with a new intense focus on fitness.

Lleyton Hewitt‘s former mentor Roger Rasheed, who was coaching rising young French star Gael Monfils in 2011, recalls that the signs were there that Djokovic was evolving.

“You could see that he was coming,” Rasheed said. ”He had tinkered with things within his game, tightening up his game in certain areas.

With the transformation complete, Djokovic reeled off 41 consecutive wins to begin 2011 and won 10 titles including three majors and five Masters 1000s.

“There were a lot of things on the court that had been finding him out whether it was the heat or the conditions and there were a lot of mid-match withdrawals.

“That all changed and all of a sudden there was this person who if you went toe-to-toe with, he wouldn‘t blow out a candle.”

A surprise loss by an injured Nadal to fellow Spanard David Ferrer in the quarter-finals helped pave the way for Djokovic who came up against Federer in the semi-finals.

Over three hours and three gruelling sets the world No. 3 put the generation change debate on the agenda by beating up on Federer to reach his fourth grand slam final.

That was almost an anticlimax with Great Britain‘s Andy Murray offering little resistance as the tennis world stood up and took notice of the new improved Djokovic.

Rasheed was impressed but it was a match a couple of months later where the penny dropped for him.

Roger Federer was caught out by Djokovic in the 2011 Australian Open semi-final.

Spain’s Rafael Nadal and Roger Federer were a dominate world tennis until 2011.

“The final in Miami where he played Rafa, it was super hot and super humid and they just went toe-to-toe,” Rasheed said.

“It took a lot out of them but he (Djokovic) just kept repeating and repeating. All of a sudden he was this different type of athlete.

“When you know that your body can do that, it can stay for that length of time, everything changes.

“That was the biggest transformation, he went from the guy who if it was 25 degrees he couldn‘t breath, to this guy who you couldn’t knock out.”

There was no stopping Djokovic in 2011 as he put together one of the greatest seasons in tennis history

He reeled off 41 consecutive wins to begin the year and won 10 titles including three majors and five Masters 1000s.

When he defeated top-seeded Nadal in the Wimbledon final, Djokovic became world No. 1 for the first time.

“The beauty was he was on the chase, he likes to hunt things down and he had Roger and Rafa in front of him,” Rasheed explains.

“He could see they were there, that they were within reach and he was learning every time he went out there against them obviously.

Djokovic’s body is in top condition as he closes in on Federer and Nadal.

“More and more that hunger and drive to get them was being fuelled, week in week out.”

A decade on and Djokovic is still on the hunt but the gap has dramatically closed.

Federer, who is missing from Melbourne Park this year, and Nadal sit together on 20 majors — three ahead of the Open‘s No. 1 seed.

What Djokovic has up his sleeve is time and durability.

His 33-year-old body is as good as it was back in ‘11 while Nadal, 34, continues to show wear and tear — a back problem saw him pull out of this week’s ATP Cup — and Federer is 39 and playing limited tennis.

As Rasheed points out it‘s not unreasonable to think Djokovic can remain at the top of his game for at least four more years.

Serbia's Novak Djokovic holds the Norman Brookes Challenge Cup trophy after beating Austria's Dominic Thiem in their men's singles final match.

“What he has shown is his body is extremely durable and that is very advantageous to him,” he said.

“And he has put that number (21 grand slams) in front of him, he has put it on the record that is what he‘s chasing now.

“Instead of saying ‘I’m not really fussed’, he has actually said ’No, I’m chasing that’ so there is massive ambition for him.

“He sees what is happening around, he knows what is coming up behind him but they‘re not there yet, not in a major over five sets, so there is a lot of space to the chasing pack.

“The next four years, that‘s 16 majors, there is a fair chance he’s going to win a fair few of those.

“So now every time he turns up to a major he‘s hunting the ultimate greatness, he’s after that number.”