By HOWARD FENDRICH AP Tennis Writer

MELBOURNE, Australia — When Carlos Alcaraz is on court for a training session, perhaps working on his newly revamped service motion, he’s doing so to buttress a game already good enough to claim four Grand Slam titles.

He’s also got his young rival, Jannik Sinner, in mind.

“The good thing for me is, when I’m seeing him winning titles, when I’m seeing him in the top of the ranking, it forces me to practice even harder every day. In practice, I’m just thinking (about) the things that I have to improve to play against him,” Alcaraz said Saturday, a day before the start of the Australian Open. “That, I think, is great for me: Having him (and) such a great rivalry, so far, just to (force me to) give (my best), every day.”

Alcaraz, 21, and Sinner, 23, head into the 2025 tennis season at the top of the men’s game, coming off a year that portended greatness for both. With Rafael Nadal now joining Roger Federer in retirement, leaving 24-time major champion Novak Djokovic as the lone remaining member of the Big Three on tour, it appears as though Alcaraz and Sinner have separated themselves from the rest of the next generation, each taking two of the four Slam singles trophies in 2024.

Forever, it seemed, the sport’s most important laurels were dominated by Federer, Nadal and Djokovic, and anyone harboring hopes of claiming then needed to defeat at least one, and often two, of that trio.

The names have changed, but the dynamic is similar.

“I feel like now, with Jannik and with Carlos, it kind of moved toward the same way, just with new guys. You have to go through them to win big tournaments. It’s as simple as that,” said Alexander Zverev, a two-time major finalist who is seeded No. 2 at Melbourne Park, between No. 1 Sinner and No. 3 Alcaraz. “They both won two Grand Slams (last) year. And they’re the two best players in the world, for sure. And you have to beat them to win the tournament.”

Sinner is the defending champion in Australia, and went on to also win the U.S. Open in September, part of a season in which he went 73-6 with eight titles – but also dealt with a doping case in which he tested positive twice for trace amounts of an anabolic steroid, blamed it on accidentally being exposed to a banned substance via a massage from his trainer and was exonerated. (The World Anti-Doping Agency appealed that ruling; a closed-door hearing will be held at the Court of Arbitration for Sport in Switzerland on April 16-17.)

Alcaraz exited from the Australian Open in the quarterfinals against Zverev last January, but then triumphed at the French Open, getting past Zverev in the final, and Wimbledon, where he won against Djokovic in the final for the second year in a row.

On Sunday, Zverev faces wild-card entry Lucas Pouille at night, after two-time defending champion Aryna Sabalenka takes on 2017 U.S. Open champion Sloane Stephens. Other top names scheduled for Day 1 action include 2024 Australian runner-up and Paris Olympic champion Zheng Qinwen and three-time major finalist Casper Ruud.

Alcaraz, Sinner and Djokovic, along with five-time major champ Iga Swiatek and 2023 U.S. Open winner Coco Gauff, all will get started Monday.

If Alcaraz, whose first major title came at the 2022 U.S. Open at age 19 and propelled him to a debut at No. 1, wins this Australian Open, he would be the youngest man in tennis history to complete a career Grand Slam, with at least one championship from each of the sport’s four most prestigious events.

“It’s truly remarkable,” former player Feliciano Lopez said, “what he has achieved in the last three years.”

Alcaraz and Sinner already are establishing quite a head-to-head rivalry, one that already has shown glimpses of the potential to become as memorable as Federer vs. Nadal, or Djokovic vs. Nadal.

“You have more eyes on us,” Sinner said, “because this is a match most people want to see.”

Overall, Alcaraz leads 6-4.

In 2024 alone, he went 3-0 against Sinner, who was 73-3 against everyone else, with setbacks only against Daniil Medvedev, Andrey Rublev and Stefanos Tsitsipas.

“When I’m playing against him, I have a different mindset, a little bit. I mean, when you’re facing the … best player in the world, you have to do something different – different preparation or different mindset or whatever,” said Alcaraz, who was 54-13 with four titles last season. “When I’m facing him, I just know that I have to play my best if I want to win. That’s it. Probably if I have a bad day against Jannik, it’s 99% that you’re going to lose.”

DJOKOVIC, MURRAY TEAM UP

Djokovic and Andy Murray have known each other for a quarter of a century. They played from the age of 12, meeting 36 times as professionals, including 10 Grand Slam matches. Yet they’ve never been able to talk shop and freely trade all sorts of thoughts – about tennis and otherwise – until now.

That’s because Djokovic got the bright idea to hire the recently retired Murray as his coach, at least through the Australian Open.

“I must say, at the beginning, it was a bit of a strange feeling to be able to share the insights with him, not just about the game but about how I feel, about life in general. Not in a negative way, but just in a way I have never done that with him, because he was always one of my greatest rivals,” Djokovic said Friday. “We were always kind of hiding things from each other. Now all cards are open on the table.”

It’s an unusual pairing that caught their sport by surprise in November, after Djokovic called up Murray to check on the possibility of teaming up. Two rivals now on the same side. Medvedev, the 2021 U.S. Open champion, drew on soccer to try to explain how out-of-this-world this relationship is.

“Imagine,” Medvedev said, “(if Lionel) Messi would become the coach of Cristiano Ronaldo. It would be strange.”

Indeed. It sure is odd to see Murray standing just steps away from Djokovic behind a baseline during practice sessions.

These are, after all, two of the greats of tennis. Djokovic owns a men’s-record 24 Grand Slam titles, including 10 at the Australian Open, and has spent more weeks ranked No. 1 than anyone in history. Murray also has been No. 1, owns three major singles trophies, was a Slam runner-up eight times – five of those losses in finals coming against Djokovic, including four at Melbourne Park – and is the only player with two Olympic singles gold medals in tennis.

“Could never quite get over the line (in Melbourne), unfortunately. This man was single-handedly responsible for that. So I’m now here to try and sabotage his chances of winning another one,” Murray joked.

“Novak asked me to help him; I was shocked,” said Murray, whose last match as a player came at the Paris Olympics in August. “I was obviously not expecting that when he called.”

Both men are 37; they were born a week apart in May 1987. Djokovic led their head-to-head series as pros 25-11, including 8-2 at the Slams. But those two losses were two of the biggest wins of Murray’s career: In the final of the U.S. Open in 2012, his first major championship, and Wimbledon in 2013, when he ended Britain’s 77-year wait for a British man to take the singles crown at the All England Club.

“We thought we’d give it a go and see if I can help,” Murray said. “Novak is not just one of the best tennis players of all-time. He’s one of the best athletes of all-time. I expected him to be an extremely hard worker. Very diligent. Always looking to improve.”

Djokovic split from coach Goran Ivanisevic last March after a dozen majors titles together and never hired a full-time replacement.

It’s not clear whether Djokovic and Murray will stick together beyond Australia.

They spent a little more than a week together in the offseason and have been working together less than a week in Melbourne.

“I was thinking about the names that I would like to have next to me for this season. I wanted to have somebody that won multiple Slams. The list is not that long. Somebody that really understands what it means to win a Slam, what it means to face the adversity, the pressure, the expectations,” Djokovic said.

“Andy just finished his playing career six months ago. It was somewhat of a surprise for him when I called him,” Djokovic added. “But I think his tennis IQ is very high. We all know that.”

GAUFF HAS WORKED ON SERVE, FOREHAND

It was a meaningless hit-and-giggle session, a mixed doubles exhibition at Rod Laver Arena just for fun and charity in front of fans a few days ahead of the Australian Open, so Coco Gauff was calling out how fast she would try to hit some serves.

Her guesses, and her deliveries, kept getting closer to 125 mph on Thursday evening, and when the 2023 U.S. Open champion and her partner, Andrey Rublev, had taken that game, one of their opponents, Hall of Famer Lleyton Hewitt, acknowledged, “Great serving.” Gauff’s response? “Thanks. I’ve been working on it.”

Yes, she has – on her serving and her forehand – and the strides made in both of those areas are among the reasons Gauff is considered one of the few women ready to challenge two-time defending champion Aryna Sabalenka for the title at Melbourne Park.

“It would be great to come home with the Australian Open trophy. But I think I’ve just learned to not put so much pressure on events, and just put pressure on development and how I’m playing. That takes the pressure off,” Gauff said. “I mean, yeah, making the semis last year and losing to Aryna, the eventual champion – I feel like I can get there and cross that line.”

Her first opponent in Melbourne will be another American who owns a Grand Slam title: Sofia Kenin, the champion in Australia in 2020 and a winner against Gauff in the first round at Wimbledon in 2023. This match will be Gauff’s first appearance at a major since she accumulated 19 double-faults in a fourth-round loss at last year’s U.S. Open to Emma Navarro.

With the help of new coach Matt Daly, who joined Jean-Christophe “JC” Faurel on Gauff’s team after Brad Gilbert was let go in September, the 20-year-old American adjusted the grips she uses for her forehand and serve in a bid to correct the two most obvious shortcomings in her game.

“It’s just been a great combo. JC has brought me a lot of footwork and shot selection in my game. And Matt has helped me with the technical side of things – my serve, specifically, and other things, as well,” Gauff explained. “It’s just a good combination that we have. I’m very thankful for them to make the transition as easy as possible, especially considering it is two people.”

So far, so good.

“She’s, for sure, improving,” five-time Slam champion Iga Swiatek said.

Swiatek had an up-close look, losing to Gauff in the WTA Finals in Saudi Arabia in November and in the final of the United Cup team event last week in Sydney. Both were straight-set results and came after Swiatek had led their head-to-head series 11-1.

As Gauff posted on social media: “new szn, better me.”

The championship at the WTA Finals felt like a big moment. It also included a victory over Sabalenka, who is currently ranked No. 1 – one spot in front of Swiatek, and two in front of Gauff.

“It means a lot to me,” Gauff said, “and playing the best of the best makes me feel confident in my game. … I want to win as many big trophies as possible and just fill the cabinet up.”

SWIATEK, SINNER DISCUSS DOPING CASES

Swiatek, a self-described “control freak,” is taking new precautions – including holding on to extra samples of medicine she takes, in case they need to be tested at some point – after a doping case she described Friday as “probably, like, the worst time in my life.”

Sinner, another player who spent time at No. 1 and tested positive in 2024, said ahead of the Australian Open he hasn’t been told when the WADA’s appeal of his exoneration will be heard in court.

“I know exactly as much as you guys know,” Sinner said in response to a reporter’s question at a news conference Friday. “We are in a stage where we don’t know many, many things.”

As confident as he repeatedly has said he is about the eventual outcome, the 23-year-old Italian acknowledged that it’s on his mind as the year’s first Grand Slam tournament is set to begin.

“Yeah, you think about this, of course,” Sinner said. “I would lie if I would tell you I forget.”

He and Swiatek, a five-time major champion, both were able to go for months last season without anyone knowing what was happening behind the scenes and that they had failed tests.

Sinner tested positive twice for trace amounts of an anabolic steroid at a tournament in March; those results – and the fact that he was cleared by the International Tennis Integrity Agency (ITIA) – did not come out until August, shortly before the start of the U.S. Open, which he would go on to win. He was cleared because the ITIA accepted his explanation: A trainer exposed Sinner to a banned substance by giving him a massage shortly after using a cream on his own injured finger.

Swiatek failed an out-of-competition drug test in August, but her one-month suspension wasn’t known until late November, after she sat out three events without revealing why. By the time her case was announced by the ITIA – which accepted that her sample was tainted because of a contaminated sleep aid – all that was left for her to serve was a week, which landed in the offseason.

On Friday, Swiatek described the initial period she was sidelined, which she talked up at the time to personal reasons, as “pretty chaotic” and said, “For sure, it wasn’t easy; it was probably, like, the worst time in my life.”

“It got pretty awkward. Like we chose for the first tournament to say ‘personal reasons’ because we honestly thought the suspension is going to be lifted soon. From the beginning it was obvious that something was contaminated because the level of this substance in my urine was so low that it had to be contamination,” Swiatek said.

“We started, yeah with ‘personal issues,’” she added, “because I needed also time to figure everything out.”

Swiatek said she was worried about what other players’ reactions would be at the start of this season.

“Besides the fact I couldn’t play, this was the worst thing for me: What people would say. Because I always worked hard to be a good example, to show my integrity, show good behavior,” she said. “Having no control over this case really freaked me out a bit. But in the locker room, I mean, the girls are great.”