Rafael Nadal is worried for the future of the game

Rafael Nadal has warned tennis chiefs that the sport faces future troubles if equipment evolution continues to make speed and power dominate skill and tactics.

On the eve of his opening match at the Miami Open, the 14-time Grand Slam singles champion said changes are needed to counteract taller and stronger players using modern racquet technology to make quick work of points and matches.

"The sport in general needs to improve in all aspects," Nadal said.

"The players today are taller than before. The racquets hit the ball harder than before. 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."

The 29-year-old Spanish left-hander said tennis must adapt for future generations to enjoy it as much as past ones have.

"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," Nadal said.

Nadal says Novak Djokovic deserves his current dominance

"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."

Nadal said it is important for tennis to develop stars and rivalries, such as he has enjoyed with once-dominant Roger Federer and with Novak Djokovic, whose 11 career Grand Slam titles include four of the past five contested.

Highlights of the semi-final clash at Indian Wells between Novak Djokovic and Rafael Nadal Highlights of the semi-final clash at Indian Wells between Novak Djokovic and Rafael Nadal

"In my opinion, it's not good if win a tournament every week a different player. People arrive at the tournament and nobody knows who are the favorites," Nadal said.

"It's difficult because the people need to support one player, so you need the stars. To create the stars you need players that have been there for a long time.

"At the same time it's good to have a combination of styles, different players that fight for the important things and one or another can win. 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."

Nadal, who has struggled with knee injuries for years, went without a Grand Slam title last year for the first time since 2004 but is not looking toward the end just yet.

"I'm happy doing what I'm doing. I enjoy playing my sport," he said. "It's about love for the game, about passion for what I'm doing and I'm going to be here until I'm unhappy doing what I'm doing."

Watch the Miami Open on Sky Sports 3 HD - your home of tennis

By purchasing a Sky Sports Day Pass for £6.99 or Sky Sports Week Pass for £10.99, you can enjoy access to all seven Sky Sports channels and watch on a TV with a NOW TV Box or on a range of devices.