“Are we overplaying the exhaustion factor?”: Isner, Sock and Querrey split Djokovic’s chances against Sinner

Former ATP players John Isner, Sam Querrey, Steve Johnson and Jack Sock analysed Novak Djokovic’s chances of reaching the Australian Open final, where he will face two-time defending champion Jannik Sinner. The Serbian survived the quarter-finals by a miracle following Lorenzo Musetti’s retirement due to injury.

It has been a strange path. Djokovic once again finds himself in the semifinals. He was eliminated at this same stage in 2024 and 2025, both times arriving after long, physically demanding runs. This time, things are different for Nole, as it is rare to reach the semifinals of a Grand Slam with so little time spent on court as Djokovic has logged so far.

The 24-time Grand Slam champion has barely accumulated 9 hours and 7 minutes on court, averaging under two hours per round. Of course, in Djokovic’s chaotic run, after overcoming the first three rounds in tight matches, he advanced from the Round of 16 following Jakub Mensik’s withdrawal. In the quarter-finals, he only managed to play two sets before his opponent retired.

Djokovic will arrive with more energy than on other occasions, though not without concerns — particularly regarding his level. In the match against Musetti, the Italian’s injury occurred when Djokovic was leading 6–4, 6–3, 1–3 (ret.). Musetti was just details away from claiming one of the most important victories of his career, but once again injuries derailed his goals. Djokovic advanced by a miracle and will arrive charged with energy for the semifinals against Sinner.

“Obviously Novak should have a lot left in the tank,” explained former world No. 8 John Isner on the Nothing Major podcast. “He basically played a three-set match in the quarterfinals. Do you feel like right now is the time that he's just going to absolutely empty the tank and go into lockdown mode?”

However, the Serbian left poor statistics against Musetti: he won just 61% of points on first serve and 39% on second serve, converted 3 of 7 break points, while dropping his own serve in 5 of 11 opportunities. Djokovic committed 32 unforced errors compared to Musetti’s 23.

“Against Sinner, he has to play even crazier aggressive tennis to try to take him out,” Isner added in his analysis. “He has to go back to his all-time great counterpunching ways and just empty the tank against Sinner, then hopefully see what happens in the finals.”

The rest of the Nothing Major co-hosts joined the discussion regarding expectations for Djokovic heading into the semifinals. After struggling significantly against Italy’s No. 2 Musetti, the task looks even more difficult against two-time defending champion Sinner, who is riding a 19-match winning streak at Melbourne Park.

“I think he has to know he can be aggressive against Sinner,” Querrey commented. “If he's going to empty the tank, it’s for one single match, and that would be the final if he gets through this.”

Meanwhile, former world No. 21 Steve Johnson emphasised that Nole will give everything against Sinner — but warned that context matters, as Djokovic has not won a set since the third round. “I think he empties the tank against Sinner because if he gets to the final, all the adrenaline will be there. If he can just get through Sinner, that’s it. He just has to get through one,” Johnson added. “Between that and the fact that he hasn’t won a set since the third round, it’s been a long time since he won a set, and he’s in the semis.”

Former world No. 8 Jack Sock also joined the discussion, arguing that the physical element will be key in determining whether Djokovic can truly challenge Sinner. “I know he’s 38,” Sock said. “Are we overplaying the idea that he’s going to get exhausted at some point? Was he tired today against Musetti after a point?”

“He also plays possum a little bit with that stuff. He loves to walk around and act like he’s exhausted after a point, then slide into 18 balls in a row and play another long point. The guy is every resource. He’s phenomenal. I feel like he’s got more in there than he puts off when he’s on the court acting tired.”

Sinner and Djokovic will face each other on Friday, 30 January, in what will be their 11th career meeting. At the moment, the head-to-head favours Sinner 6–4, with the Italian having won the last five clashes in a row, including semifinals at the 2024 Australian Open, Roland Garros and Wimbledon 2025.