Andy Roddick believes Novak Djokovic has been reshaping his game for years, but not through anything as eye-catching as Roger Federer’s SABR. In Roddick’s view, the Serbian’s changes are far more practical, built around the reality of a body that no longer does everything it once did.

Roddick, who went 3-21 against Federer, said the 24-time major champion has made clear adjustments as he moves through the later stages of his career. Djokovic has increased the pace on his second serve, looks to finish points earlier, and comes forward more often than before. Those shifts, Roddick said, are designed to compensate for being a step slower and no longer carrying the same endurance.

The contrast with Federer’s 2015 SABR experiment is central to Roddick’s argument. He recalled how the Swiss used it at the Cincinnati Masters, when Federer essentially half-volleyed Djokovic’s serve and rushed the service box. It paid off in that final, though Djokovic later identified the tactic and defeated Federer in four sets in the US Open final.

Roddick called SABR a “circus”, in part because Federer used it so sparingly after those two tournaments. Djokovic’s evolution, by comparison, is constant and deliberate. On Served, Roddick said, “SABR was a bit of a circus. Like Roger would do it and it was fun, but did we ever see him really do it more than like one time? Every third set, it wasn’t something that you could go to all the time. Novak has already made adjustments.

“The second serve goes bigger, goes into the body. He doesn’t defend as well out of the corners. You might see him making more errors. That’s because he is trying to get on the front foot more often.

“It’s not as nuts as like SABR, where we’re all just waiting for him to be like, I mean, basically Roger is playing a game of horse (shooting a basketball from different locations on the court), but during matches, ‘Um, can I pull this off? Yeah. I mean, he’s certain.

“Novak serves and volleys way more than he used to. Every player who was fantastic at defence, you lose a step. How do you make up for that? It’s by getting on the front foot and playing less defence. How has that done? It’s by hitting bigger from the baseline.”

Roddick did note that Djokovic still can summon vintage defence, including in the final-set tiebreak of his quarter-final win over Felix Auger-Aliassime. But he added that such stretches are harder to sustain now. As Roddick put it, “I think we’ve seen Novak do that. I don’t know that you see him as often settle in and defence [it] up. Now he still does it when he needs to. The fifth set buster against Felix Auger-Aliassime [at Wimbledon], he went vintage, but can his body take that defensive load for five sets? I think the answer is no.

“Now it’s not as like obvious as SABR or Roger hitting one handed backhand and return winners with a bigger frame or something to talk about. But he’s already made a bunch of adjustments.”

Learner Tien has acknowledged a lingering physical problem after his straight-sets loss to Ben Shelton in the Canadian Open semi-finals.

The 20-year-old had arrived at the match with confidence after winning the first two meetings between the pair, but Shelton ended that run with a 6-2, 6-3 victory on Wednesday. It was still a positive week for Tien after a difficult stretch of results, yet the left-hander’s condition now appears to be the bigger story.

Tien had strapping on his left arm against the defending champion, and the issue is already being managed with Cincinnati ahead. The concern has not gone away, and he explained in his post-match press conference that it has been bothering him for more than three weeks.

He said in his post-match press conference, “I’ve been trying to manage it [the arm issue] for maybe longer than three weeks. It’s kind of just always been there. I was supposed to play doubles this week. I ended up not playing, which is good for me.

“It’s just kind of been nagging at me. Sometimes I warm up and I don’t really feel it, and then towards the end of practice I start to feel it. And then sometimes I feel like if I really go for a serve, like something bad will happen.

“And I’ve been doing my best just to manage it, and but it’s been irritating and it’s just kind of been there. I’ve kind of found a way to play through it this week, but it’s not ideal I’d say.”

He also sounded uncertain about how the issue may affect his upcoming schedule. Along with Cincinnati, he is set to play US Open mixed doubles with Amanda Anisimova before the singles event the following week.

When asked about his next steps, Tien replied, “I don’t know. I think if it’s something that isn’t serious, that I won’t injure it further, if I play through it, I mean, I love to play.

“I mean, I always do just try to go out and play no matter how I’m feeling. That’s just kind of how I am. I always to finish matches; I always want to play matches, whether something is hurting or not. So I’m always going to go out and play, if I’m able to, if something bad won’t happen if I play through it.

“I’m going to take a couple days off now. I don’t think I play till Sunday in Cincy. I’ve kind of just been managing it the last few weeks, and I think a couple days off will be good for it.”

Tien said he was not close to withdrawing against Shelton, insisting he will keep competing whenever possible. If he does eventually pull out, attention may again turn to the demands of the schedule and the two-week Masters 1000 events.

Three younger players have been put forward as possible candidates to become the sport’s “third guy” behind Carlos Alcaraz and Jannik Sinner, in what amounts to a slight on Alexander Zverev.

The discussion comes at a time when the ATP Tour has again been left without some of its biggest names. Alcaraz remains out with a wrist injury, while Sinner withdrew from Cincinnati because of a knee problem. At the Canadian Open, the picture was similar, with Sinner, Alcaraz and Novak Djokovic all absent, and Zverev crashing out early.

Montreal’s quarter-final stage showed just how open the moment is for the next generation. Brandon Nakashima, 25, beat Luciano Darderi, 24, while Ben Shelton, 23, moved through against Jakub Mensik, 20. Arthur Fils, 22, was defeated by 19-year-old Rafael Jodar, and Learner Tien knocked out Daniel Merida, 21.

Those results have helped fuel the idea that an outsider could use one of these Masters 1000 events to build belief against the game’s established leaders. Zverev, 29, did win this year’s French Open when the Italian went out early and the Spaniard was sidelined, but the broader picture still points toward Alcaraz and Sinner as the dominant forces.

Serena Williams’ coach Rennae Stubbs believes the opportunity is there for others to break through. On the latest episode of The Rennae Stubbs Tennis Podcast, she pointed to Jodar and Shelton, who are sixth and seventh respectively in the ATP Tour Race, while also naming Fils and Tien as players capable of taking a step forward even though their results this year have left them outside the top 10.

She said on the latest episode of The Rennae Stubbs Tennis Podcast, “This is an opportunity for somebody to start winning these tournaments and say, ‘Ok, am I the third guy?’ Winning in Canada and then going to Cincinnati and winning those tournaments because neither of them [Alcaraz and Sinner] are going to be there again.

“There are no more excuses, guys. The two best players in the world are not playing so who is going to step up to the plate?”

Stubbs also said Jodar is beginning to “knocking on the door to win these big tournaments” and suggested another major title for him, Shelton or Fils could strengthen the belief that they can compete with Sinner and Alcaraz “when they are healthy”.

The four-time women’s doubles major winner added, “This is exciting. What we need in men’s tennis is for one of these young guys to step up to the plate now. By winning a Masters 1000 title at this stage.

“Imagine if a Learner Tien or a Rafael Jodar steps up and wins this Masters 1000; it has to give them so much confidence to go into a US Open and say, ‘Why not?’ There is a possibility Alcaraz and Sinner are going to be there.

“But it really helps when you are winning a lot of matches and you are beating all these great players and the only ones you are not beating are those two who are not there but it will certainly help you going into matches like this against those great players and think, ‘Maybe it’s my time as well’.”