INDIAN WELLS, Calif. — Rafael Nadal, who had just defused Nick Kyrgios in three tense sets to reach the semifinals of the BNP Paribas Open, was trying to focus on the questions.

But Nadal kept getting distracted at the news conference on Thursday, looking at the television in the corner of the room that was showing the quarterfinal match between his 18-year-old Spanish compatriot Carlos Alcaraz and the defending champion, Cameron Norrie.

“It was a break point,” Nadal explained as he shifted his gaze back to the reporters at hand. “Sorry, about that.”

Despite his youth, Alcaraz, born in Murcia and coached by the former No. 1 Juan Carlos Ferrero, has long been considered a potentially great player by tennis cognoscenti inside and outside Spain.

But potential and reality are converging quickly. After defeating Norrie, 6-4, 6-3, Alcaraz is into the semifinals for the first time at a Masters 1000 event. He will face Nadal, the ultimate Spanish tennis champion, who holds the men’s record with 21 Grand Slam singles titles and is unbeaten in 2022.

Nadal, 35, is nearly twice Alcaraz’s age and defeated him, 6-1, 6-2, last year on clay on Alcaraz’s 18th birthday in the round of 32 at the Madrid Open. Alcaraz needed treatment for an abdominal injury early in that match, but he was also nervous and impatient as he faced one of his idols.

But Alcaraz’s second match with Nadal, which will come on a gritty hardcourt on Saturday, could be considerably more compelling. Since their first meeting, Alcaraz has soared into the top 20, reaching the quarterfinals in his first U.S. Open last year, winning the Next Gen ATP Finals in Milan and then recovering from Covid-19 to win 11 of his 12 singles matches so far in 2022.

“Carlos is not even the future; he’s the present,” said Paula Badosa, the top-ranked Spanish woman and reigning singles champion in Indian Wells.

Saturday should provide an excellent sense of how far Alcaraz has come. Hardcourts should not be his best surface. He grew up, like Nadal, playing primarily on clay in Spain. But he now practices regularly on hardcourts at the academy in Villena where he trains under Ferrero. And as Alcaraz’s deep run at the U.S. Open made clear, he knows how to move, slide and entertain on this surface, too.

Win or lose on Saturday, Nadal believes Alcaraz is the real deal.

“I think he’s unstoppable in terms of his career,” Nadal said. “He has all the ingredients. He has the passion. He’s humble enough to work hard. He’s a good guy.”

That is unusually high praise from Nadal, normally wary of adding to the burden of expectations on emerging stars, but he went further, explaining that Alcaraz reminds him of himself at age 17 or 18.

Nadal was a genuine teen prodigy who won the first of his 13 French Open singles titles at age 19 in 2005 and would most likely have won it earlier if injuries had not forced him to skip the tournament in 2003 and 2004.

Alcaraz’s smile was as big as his forehand when informed of Nadal’s comments.

“It means a lot to hear those kinds of things from Rafa about yourself,” he said in Spanish, which he speaks much more fluently than English. “Rafa’s been through all kinds of things and has been on the top for many years, and for him to make those kinds of comments is really inspiring.”

He is the youngest men’s semifinalist at Indian Wells since the American Andre Agassi in 1988 and like Agassi, he is a natural crowd pleaser with a flashy game and quick-strike power. But unlike Agassi, he has blazing speed. On Thursday night, Alcaraz reached shots that would have been winners against most players, and earned a standing ovation from the crowd after one corner-to-corner-to-corner rally.

“It’s very cool to see him that focused and engaged and maximizing what he’s got with all the talent that he’s got,” Norrie said. “He was too good today for me.”

But tennis is a brutally competitive and grueling game. Injuries can change even the most gifted players’ trajectories: See Juan Martin del Potro, the Argentine star with the thunderous forehand whose career appears to be over.

But Alcaraz, for now, is an all-court marvel: predatory in the backcourt and forecourt; able to rip airborne groundstrokes or hit feathery forehand drop shots; able to play defense far behind the baseline or move forward to smack second-serve returns on the rise.

“He walked all over me, and not because I was tired, but because of his physicality,” Gaël Monfils, the French star, said of his loss, 7-5, 6-1, to Alcaraz on Wednesday. “At some point, you just can’t hang in there anymore.”

Nadal is in the midst of a revival: undefeated this season at 19-0 after winning three tournaments, including the Australian Open by rallying from a two-set deficit in the final against Daniil Medvedev.

Nadal has worked his way through the draw here despite the chronic foot problem that ruined the end of last season for him and continues to cause him pain. He could have skipped this tournament to rest and prepare for his beloved clay, just as he is skipping next week’s Miami Open. But he enjoys Indian Wells, staying at the home of the tournament owner, Larry Ellison, and playing golf regularly.

His tennis matches have been no vacation, however. He came within two points of defeat against the young American Sebastian Korda in his opening round before rallying from two breaks down in the third set. Kyrgios, one of the game’s biggest servers and flashiest shotmakers, pushed him to the wire.

They remain quite the contrasts: Nadal the maximizer of potential; Kyrgios the flickering flame. Nadal is deliberate, sometimes ponderous, between serves and points. Kyrgios plays as if he has a plane to catch. Nadal has never thrown a racket in anger in his pro career; Kyrgios threw his twice on Thursday, the second time after losing the match, 7-6 (0), 5-7, 6-4. The racket rebounded off the court and flew toward the head of a ball boy standing near the back wall, who dodged it.

Kyrgios, booed as he left the court on Thursday, has already been suspended by the men’s tour once in 2016 and put on probation a second time in 2019 for misbehavior. He risks another sanction after Thursday’s match, and the tour would be wise to crack down more convincingly on player tantrums. Last month, Alexander Zverev took four swings at an umpire’s chair, narrowly missing the umpire, in Acapulco, Mexico, and received no further suspension after being defaulted from the tournament.

“When you allow the players to do stuff, then you don’t know when is the line, and it’s a tricky thing,” Nadal said.

The Spaniard is now 6-3 against Kyrgios, who, for all his evident gifts, has yet to get past the quarterfinals in a Grand Slam singles tournament or win a Masters 1000 title.

Nadal is one of the great champions in any sport and with victory secured and the news conference completed, he took a few more moments in front of the television to watch more of Alcaraz’s match and consider Saturday and beyond.

“It’s great, honestly, to have such a star from my country,” Nadal said. “Because for the tennis lovers, we’re going to keep enjoying an amazing player fighting for the most important titles for the next I don’t know how many years. A lot of years.”