"Rafael Nadal has the best attitude necessary for the Calendar Slam" - Todd Martin

Rafael Nadal has the "best attitude necessary" to achieve the calendar-year Grand Slam, said former World No. 4 Todd Martin.

Martin, now CEO of the International Tennis Hall of Fame, shared his thoughts on Nadal and Novak Djokovic in a tweet by journalist Sasa Ozmo.

Aside from discussing Djokovic and Nadal's strengths, with the duo posing the "biggest challenge" for the remaining players' respective quests for the Wimbledon title, Martin also touched on the Serb and Spaniard's Calendar Slam dream that was last fulfilled by Rod Laver in 1969.

The 1999 US Open finalist compared the two greats' respective runs, saying that he thought Djokovic would achieve it last year. But the 20-time Grand Slam champion faltered amid the pressure in the US Open final against current World No. 1 Daniil Medvedev.

However, he said Nadal, who has a shot at the feat after winning the first two Majors for the first time in his career, has the mentality to thrive.

"I thought Novak was going to win the Calendar Slam last year in New York. Generally, it seems to me he doesn't enjoy the pressure, but he can fight against it very well. I had a feeling that the pressure was going to bring out that 'There is absolutely no way I'm losing this' mentality from him, but it didn't happen, and Medvedev played great as well," said Martin.

"Long-term, Nadal is so focused on that process: what do I have to do today, what do I have to do right now. That's the way he thinks and in my mind, he has the best attitude necessary for the Calendar Slam. This place can make anyone nervous, but maybe Nadal won't feel it because of the way he thinks," he added.

Rafael Nadal faces Indian Wells tormentor Taylor Fritz in Wimbledon QF

Rafael Nadal advances to his eighth Wimbledon quarterfinal

Rafael Nadal last locked horns with Taylor Fritz in the Indian Wells final last March. The match ended with a victory for Fritz and a six-week layoff for Nadal, who incurred a stress fracture on his rib.

The Spaniard will look to exact revenge as he squares off with first-time Grand Slam quarterfinalist Fritz at Wimbledon on Wednesday. Armed with experience on the big stage, Nadal will look to get past the American and stay on course for a record-extending 23rd Major and a Calendar Slam.

Nadal spoke about his upcoming clash with Fritz in his post-match press conference on Monday.

"He's playing well, he's having an amazing year, winning his first Masters 1000 — against me, by the way, in the final," said Nadal.

"It's going to be a tough match, but we are in the quarterfinals of Wimbledon so what can I expect?" he added.