Andy Roddick admits there has been a “shift” in tennis for Novak Djokovic, but warned that anyone who suggests the tennis great should retire should “shut up”.

For the second consecutive year, Djokovic came up short against Jannik Sinner in the semi-final as he once again lost in straight sets against the world No 1.

The Serbian appeared to regain his title-winning form when he reached this year’s Australian Open after beating Sinner in the semi-final, but then lost against Carlos Alcaraz before making a shock third-round exit from the French Open.

The 39-year-old’s latest defeat to Sinner at the All England Club means his wait for a 25th Grand Slam continues with his last major success coming at the 2023 US Open when he beat Daniil Medvedev.

Naturally, when Djokovic fails to win a major, there is speculation about his future and some believe he has now fallen too far behind the likes of Sinner, Alcaraz and Alexander Zverev.

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But former world No 1 Roddick insists the 24-time Grand Slam still “seems happy” and any “jackass” that says he should quit should “shut up”.

“I think Novak for so long was that guy who everyone had to play perfectly against to beat him, right, and that includes the best players in the world,” he said on the latest Served with Andy Roddick podcast.

“Now I think he is the one that has to play perfectly against a couple of guys to get that win and I think that’s the shift.

“He’s playing part-time tennis and he’s still making the semis of majors. He made a final in a semi in the last three majors. It’s absurd.

“On the one point, it’s so hard to do… like that’s a career year for great players, a lot of really great players. I’m going to offer you the simplest solution.

“If his family likes travelling, if he still likes playing, he seemed happy in his press conference. It wasn’t as if, you know, I don’t know that he gets run out of the building and he’s devastated. You know, it didn’t come off that way. I saw a couple of clips and he was pretty matter-of-fact. He might just enjoy it.

“I don’t know, I don’t think anyone should weigh in about when he should stop. I know there’s going to be an article tomorrow somewhere where some jackass is going to say, ‘He should stop’. Shut up, he’s so much better than you currently than you will ever be at your job. That’s ridiculous.

“I don’t think he’ll ever let it get to like that tragic state where there’s three second-round losses in a row. I just don’t see that happening and he’s too good. We’re not close to that.

“It’s just he now has to be the guy to play perfectly against the top guys, whereas for so long you had to play perfectly against him.”