'He's a dangerous player.' Rafael Nadal nailed why we're so frustrated with Nick Kyrgios.

As Nick Kyrgios prepared to face Rafael Nadal in the second round of Wimbledon, he reflected on how there was no love lost between the pair.

He joked that he and the Spaniard were unlikely to grab a beer together at Wimbledon pub the Dog & Fox.

“I don’t know him very well. We have a mutual respect, but that’s about it.

“That’s just how it is. I get along with people, some people I don’t get along with.”

Side note: There’s been a lot of controversy of Channel 7’s decision to bump Ash Barty’s Wimbledon match for Kyrgios’. Post continues below video.

Nadal did not respond to Kyrgios’ comments about their personal relationship, instead choosing to focus on their upcoming match.

Nadal knows that Kyrgios poses a real threat, having lost to the Aussie earlier this year in Mexico.

“My thoughts are very clear: I play against a top talent player, a very dangerous player when he wants to play tennis,” said the world No. 2.

“Normally against the best players, he wants to play tennis. When that happens, he’s a very dangerous opponent.”

This comment was… actually pretty scathing.

Kyrgios copped lots of criticism after his first round match against fellow Australian Jordan Thompson because he dropped the fourth set in just 18 minutes before coming back to win with a very dominant fifth set.

Many tennis fans believe he tanked the fourth set on purpose – and Kyrgios himself said it was “a tactic” in his post-match press conference.

That 'tactic' of giving up or of not trying is what Nadal was talking about.

It is exactly what is so frustrating about Kyrgios.

He is, undeniably, a talented tennis player. Few players - especially at just 24 years old - can boast as many wins against the sport's top rated players as he can.

Kyrgios' head-to-head record against Nadal is 3-3, as it is with three-time grand slam champion Stan Wawrinka. He's beaten Roger Federer once in six attempts and is unbeaten - yes, he's 2/2 - against world No. 1 Novak Djokovic.

Asked why he holds such a strong record against the best players in the sport, Kyrgios said: "It's just me," the BBC reported. "I don't know what to say. I just love playing them.

"I can't wait [to play Nadal]. As soon as the draw came out, I was super happy that I saw him in my section. I mean, it's more exciting."

It's true what they say: to be the best, you must beat the best.

But it's so much more than that. To be the best, you must be passionate and proud, willing to put in the hard work and make sacrifices when you need to.

You need to approach every game - whether it's against the best in the world or a player who barely makes the top 100 - with the same amount of desire and respect.

Kyrgios does not do this.

In fact, he often just seems... disinterested.

When we tune into sport, it is to watch hard-working, talented people push themselves to their limits. To constantly try and better themselves and their opponents. To want to win.

With Kyrgios, there's never any guarantee that that is what we're going to get.

If he doesn't try, and if he doesn't care to try, why should we?

Thursday's (Friday morning AEST) Wimbleton contest between Kyrgios and Nadal is a much anticipated rematch of February's Mexican Open match where the Australian beat Nadal and then called him "super salty" in defeat.

Given the status of his opponent, Kyrgios is likely to give it his all. If so, it will be must-watch tennis.

But what if he wins? His record against one of the best to ever play the game of tennis will get even more impressive, which is great - but what if his next match is against a lesser-ranked player? What if he doesn't care about the next game? Will he go back to playing halfheartedly? Like he doesn't want to be there?

That's not the type of sportsperson we should be invested in. That's not the type of sportsperson who inspires fans and who is backed proudly by a nation.

A career in professional tennis cannot solely be games against the Nadals, Federers and Djokovics of the world. There's more to it, and Kyrgios doesn't seem to want to bother with the rest.

Nadal was right: Kyrgios is a real threat on the tennis court - if he bothers to show up.

Thank goodness we have Ash Barty.