On Saturday 18 January, Eurosport shared an image on social media with the caption "Some things never change".

The belief that athletes lose speed when they pass 30 isn’t universal. It may be that speed of recovery is the biggest difference. If a 25-year-old footballer plays a game on a Wednesday evening, he will be more ready for a Saturday afternoon game than his 35-year-old teammate. But if the 35-year-old was well rested, perhaps he’d be as quick as he ever was.

Djokovic played Jiri Lehecka in round four of the Australian Open, and showed at 37-years-old he’s still one of the quickest players on tour.

[2:03] These kind of points have become so routine for Djokovic that the Eurosport commentator’s “Yeah, perfect” is matter-of-fact rather than astounded. In the first set, Lehecka plays a good drop shot. Djokovic sprints to the sideline, picking the ball up from about a foot off the ground, while sliding on the hardcourt, his trailing foot on its side, perfectly balanced. He plays a tight angle crosscourt, giving himself time to recover for Lehecka’s reply. Djokovic is more than ready and calmly pushes a winner down the line.

[2:26] There was a similar point two games later. They’ve exchanged a few shots and Lehecka plays good forehand wide and deep to push Djokovic back behind the “Melbourne” sign. Recreational tennis clubs don’t even have this much room – Djokovic would be behind the fence.

Djokovic sprints forward as soon as he’s played his shot, as he knows Lehecka will try and use the space. Again it’s a good drop shot, but again Djokovic executes a perfect slide. He pushes the ball down the line, forcing Lehecka to stretch, and then wrong-foots him with a volleyed winner.

[3:01] The first point in the next game was even better. This time it’s Djokovic serving. It’s a safe serve which gives Lehecka a chance to get on top of the rally. Lehecka hits a good pacey forehand down the line. Against nearly every other player in the world, he’d win the point from here.

But Djokovic’s dynamic balance and core strength means he can control a smart, short ball crosscourt, with his classic sliding, open stance backhand. Lehecka had hit a good shot, but now he’s running from the right baseline corner to the left sideline. He plays a decent approach and gets to the net alright, but his first volley isn’t good enough. Djokovic anticipates Lehecka’s second volley and stretches even further now, hitting a winner down the line. Djokovic’s speed, stretching, and balance would be remarkable even without a ball and opponent involved.

[7:10] The next game, Lehecka might think he’s finally got Djokovic with a drop shot. But Djokovic somehow reaches even this one, sliding and stretching so low that his left hand touches the ground.

Alcaraz

The man Djokovic met in the next round, Carlos Alcaraz, has been immensely influenced by Djokovic. Alcaraz and Jannik Sinner are capable of similar counterpunching open stance backhands.

[5:10] Here Alcaraz turns a point on its head. Jack Draper has hit a good serve and volley, and although Alcaraz anticipates the volley going into the open court, he has the speed and dynamic balance to curve his run and meet the ball with a slide, his left hand touching the court like Djokovic’s.

But some things do change

After over two decades on tour, 24 Grand Slam titles, 40 ATP Masters 1000s, seven ATP Finals wins, and an Olympic Gold, Djokovic’s body has been worn and torn. Over the past year, injuries have affected his performances. In last year’s Wimbledon final, his service action and movement were compromised after he’d had knee surgery only a few weeks before the tournament.

On Tuesday, in the Australian Open quarter-finals against Carlos Alcaraz, Djokovic injured his hamstring and was forced to take more risk. He somehow came through in four sets.

In his semi-final against Alexander Zverev, Djokovic tried to finish points quicker than normal. Instead of his trademark backhand, he often sliced, presumably not wanting to put as much weight on his left leg. Rarely was his trademark stretching, open stance backhand seen. After the first set tiebreak, he retired. “I did everything I possibly can to basically manage the muscle tear that I had,” Djokovic said after the match, but it was not enough.

The Eurosport commentator said after Djokovic had shook Zverev’s hand, “He hired Andy Murray, but Murray can’t do anything about that.” The other: “He can’t fight Father Time.”

Djokovic said, “It is true that [I have been] getting injured quite a bit the last few years. I don’t know what exactly is the reason for that, maybe several different factors. But I’ll keep going, I’ll keep striving to win more slams. And as long as I feel that I want to put up with all of this, I’ll be around.”