Mumbai, Sept. 4 -- Apart from the downside of having to miss his daughter's birthday, Novak Djokovic is exactly where he would have hoped to be coming into the season's last Grand Slam: in the last four, just like the first three Slams. Now is when things have become a lot more difficult for the 38-year-old this year. Carlos Alcaraz awaits in the US Open semi-final. It's the same stage where Djokovic has exited in this season's three Slams due to an ageing body (retired against Alexander Zverev at Australian Open) and younger challengers (lost to Jannik Sinner at French Open and Wimbledon). Now is when Djokovic desperately seeks an extra push to lift him against his current two biggest rivals that, at this stage of Slams, invariably lurk. Alcaraz, 22, has been flying in New York, making a Slam semi-final without dropping a set for the first time in his career. Djokovic has been huffing and puffing physically and, at times, barely "trying to survive" in contests, as he analysed parts of his performance in the 6-3, 7-5, 3-6, 6-4 quarter-final victory against Taylor Fritz. Now is when Djokovic has felt like his tank runs half-empty by the time he steps on court to take on these twenty-something major champions. How loaded up the 24-time Slam champion's tank feels could well determine which way this much anticipated semi-final will go on Friday (Saturday morning IST). "Let's see in two days' time," Djokovic said. "Good thing is that I have two days without a match, so that helps a lot." What also helps from a Djokovic viewpoint is that he has a far better matchup with Alcaraz than Sinner, and that there are certain facets of the game where the Serb can ask some tough questions of the Spaniard. Not only does Djokovic have a positive head-to-head record against Alcaraz (5-3), he has also never been beaten by Alcaraz on hard court. Their first meeting at the US Open comes after two consecutive wins for Djokovic in their rivalry - at the 2024 Paris Olympics final and the 2025 Australian Open quarter-final. While Paris was a different surface and occasion, that 4-6, 6-4, 6-3, 6-4 win in Melbourne this year in particular is where Djokovic could take a cue from in New York. A lot, for starters, will rest on how well Djokovic can fire up his first strike. His serving against Fritz wasn't at its finest. Against Alcaraz, whose returns have been on song, it could spell trouble. In Melbourne, Djokovic took time to get into his serving groove, which resulted in the dropped first set before the first serve win percentage rose in the third and fourth sets. Finding those quality first serves will be critical for Djokovic. So will attacking the Alcaraz second serve. That was arguably the biggest differentiator between them in Melbourne. Djokovic ensured Alcaraz won just 11 points behind his 33 second serves, a low 33% compared to Djokovic's 58%. On set point to bag the second set, Djokovic unleashed a blazing backhand return in response to Alcaraz's second serve. Alcaraz's serving has improved from Melbourne, as his 68% second serve points won in New York (highest among men) show. Djokovic's receiving though remains top notch (he sits atop in the most first serve receiving points won and third for the second serve). Djokovic made a visible change between the first and second sets in Melbourne: he came forward more often in the second (net points went from 8 to 13). It wouldn't mean Djokovic frequently dishing out drop shots but building rallies in a way that can give him the chance to approach. He won some key points in the second set with that court positioning. This goes for during and between play. Alcaraz can be unstoppable if he settles into a rhythm. Djokovic could look to break that with slices and volleys. There was one point in the fourth set in Melbourne where Djokovic looped a defensive forehand volley from behind the baseline. It made an approaching Alcaraz backpedal and squander the point. Alcaraz will also have to gauge against Djokovic possibly breaking the overall rhythm of play. He took a medical timeout with Alcaraz 5-4 up in the first set in Melbourne, returning with a taped upper left leg. It hampered Djokovic a bit, but dented Alcaraz's momentum. Djokovic has had a few medical timeouts in this US Open too. At 38, he finds himself asking similar questions of his physical state ahead of another semi-final. "The next couple of days is really key for me to get my body in shape and ready to battle five sets, if needed," said Djokovic. The fresh, high-flying Alcaraz sure will be ready for a battle. And more. "I played a lot of times against him," he said. "I really want to revenge."...