Nadal advises Kyrgios to play all the matches the way he did Thursday

LONDON—Rafael Nadal says Nick Kyrgios has the talent to win Grand Slams but must show passion and consistent effort to do it.

Nadal defeated Kyrgios in four thrilling sets during their second-round meeting at Wimbledon keeping a more even level during a tense and sometimes tetchy encounter.

Following the match, the No. 3 seed assessed Kyrgios's game much as he has before.

"As I said plenty of times, he's a very top, talented player," said Nadal. "But there is a lot of important things that you need to do to become a champion."

Kyrgios acknowledges that he is "not the most professional guy," saying, "At the moment I don't think I can contend for a Grand Slam."

Nadal stressed that commitment is important to success. "Without really loving this game that much, is difficult to achieve important things."

While Kyrgios tends to perform his best against the best players, sometimes against other opponents he has appeared to lack motivation.

Nadal pointed to Kyrgios's erratic five-set win against Jordan Thompson in the previous round, saying these were the kind of matches he has to win regularly to get further into tournaments and contend for titles.

"Anyway, with his talent and with his serve, he can win a Grand Slam, of course. He has the talent to do it," he said. "Is true that things can be completely different for him if he wants to play all the matches the same way that he try today."

"But if you see the first round against Jordan Thompson, he was able to win the match, but the intensity on court, the way that he played, the way that he was focused, was different than today.

"He likes to play these kind of matches. But to win important things, you don't need to play against the top players, you need to play against another players that they are so good, too. You need to win [those] matches."

Some of Kyrgios's tactics during the match—complaining about the amount of time Nadal was taking between points, serving underhand, arguing with the umpire—appeared to bother Nadal, especially when Kyrgios hit him with a ball at net.

Nadal insisted he had not been angry, but said Kyrgios should refrain from such behavior.

"Honestly, is about we are in a game that the history of this sport is about respect and is about playing fair during the whole time," he said. "I don't say Nick does this stuff to bother the opponent, but is true that sometimes he's dangerous. When he hit the ball like this, is dangerous. Is not dangerous for me, is dangerous for a line referee, dangerous for a crowd.

"Is not about I am angry about him at all. It's about I want to play a match of tennis."

Kyrgios, who has been in the top 15, is No. 43 in the rankings.