Tennis has had no shortage of bad publicity in 2016.

An investigation into alleged widespread match-fixing marred the Australian Open in January and just a few weeks later the tennis world was rocked by Maria Sharapova’s positive drug test.

More recently, the gender pay debate was reignited by inflammatory comments from key figures in the sport, while closer to home the antics of Nick Kyrgios and Bernard Tomic have filled column inches.

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Yet more trouble is ahead for the sport, according to 14-time grand slam winner Rafael Nadal, who is worried that tennis will become all about power and strength instead of finesse and strategy.

The Spaniard spoke candidly on the future of tennis before the Miami Open, urging the sport’s powerbrokers not to become complacent.

‘Tennis can be in trouble for the future’

Nadal said his sport needed to improve “in all aspects”.

A familiar recent scene: Djokovic the winner, Nadal the loser. Photo: Getty

“The players today are taller than before. The racquets hit the ball harder than before,” he said during a press conference.

“Same time, it’s true that nothing changed in our sport in terms of rules, how high is the net, everything.

“People get emotional when the points are intense, long. If every time we make that happen less often, it’s obvious our sport can be in trouble for the future.

“Tennis has been tremendously successful for a long time.

“The sport is healthy. But it’s obvious at the same time we need to move, to predict the future.

“I’m not talking for my generation but for the next generation.

“The people like the drama, the rallies. I don’t remember amazing matches that was only one serve and one shot.

“The matches that people remember most are matches that are slow matches with unbelievable points and the applause of the people or the emotions of the people are not only with one serve and one shot.”

Djokovic domination has been ‘too much’

While acknowledging that it was “not good” for tennis if a different player wins a tournament each week, Nadal said world number one Novak Djokovic had had his own way for too long.

Nadal says he is still very passionate about tennis. Photo: Getty

Djokovic won three grand slams in 2015 and now has 11, while he also holds the edge on Nadal in their head-to-head record.

The Serbian leads 25-23, but has won 10 of the last 11 matches against Nadal.

“It’s good to have a combination of styles, different players that fight for the important things and one or another can win,” he said.

“That has happened the last 10 or 12 years.

“It’s obvious now it’s better for Novak. For last year-and-a-half, two years, one is dominating. Maybe too much. But he deserves it.”

No thoughts of retirement

The 29-year-old has not won a grand slam since the 2014 French Open and has battled persistent injury problems in recent times.

That has triggered speculation that he may retire earlier than many of his counterparts. But Nadal said calling it quits was simply not on his radar yet.

“I am happy doing what I am doing,” he added.

“I enjoy playing my sport. It’s about love for the game, about passion for what I am doing.

“I am going to be here until I am unhappy doing what I am doing.”