Alexander Zverev was battling against Jannik Sinner on Centre Court in the men's singles final at Wimbledon, sparking injury concerns in one of tennis' biggest matches

Alexander Zverev sparked injury concerns when he slipped on the turf, holding his knee in pain, during the Wimbledon men's singles final on Sunday evening. The German was deep into a third set against Jannik Sinner for the coveted Grand Slam title when disaster struck.

With Zverev taking the first set 7-6 and Sinner clinching the second with the same scoreline, the two men were tied at 3-3 in the third; advantage Sascha. After three returns from Sinner, the ball made its way to Zverev's right, with the 29-year-old slipping slightly as he made it to the shot.

However, with the next return going to Zverev's other side, he looked to have slipped again once more, hyperextending his right knee in the process. The ATP No. 3 was then spotted clutching his right knee in pain, as a shocked Sinner ran over to his side of the court to check up on his opponent in a showing of sportsmanship.

BBC commentator Andrew Castle was quick to ponder what had caused the issue in Zverev's knee, as he asked: "Is that an impact?" before Andre Agassi replied: "That's a hyperextension, when that happens you're lying on the ground hoping the pain doesn't indicate it's something you're not going to recover from."

While Zverev was ultimately able to continue without calling the trainer, he seemed to be struggling in-part, with Agassi claiming that since the slip, he had missed more first serves than he had made.

And his frustrations were on full display when he lost the eighth game in the first set, throwing his racket in fury. During the break, meanwhile, Todd Woodbridge explained what he had seen from Zverev as he watched on from the stands of Centre Court.

He explained: "Obviously, I'm very close to it at that moment. But look, when he rolled over on his back, he looked up to Jannik and said, 'I'm fine, I'm okay.' It was a turning point in the momentum and a change of rhythm as much it is as an injury I think.

"You talk about key points, it was Sinner's set all the way. Remember the opening game from love-30? That was such a massive game because Zverev's body language had started to drop there.

"And once he dropped serve there, and Jannik goes to serve, he's looking up at his box and he's going, 'What do I do?' and he gives them a sarcastic little clap of his racket as if to say, 'Come on, make more noise for me. Get going.'

"He can't afford to dive into that type of negativity, he's not going to get out because Jannik Sinner is so strong mentally. He's stayed so perfectly to hang onto that second set. And he had the upper hand there. It could have gone either way.

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"I realise that, as Andre just said, these small moments are so, so important. But he has to come out and be incredibly positive, and I'm not sure that's his go-to mantra when things like this are happening. I hope that he doesn't feel the 'poor mes, I'm close, and here we go again.'"

There would no doubt have been flashbacks to that awful injury that put paid to his hopes at the French Open four years ago, where he was forced to retire from his match against Rafael Nadal in the semi-finals. Zverev twisted his ankle severely as he chased a ball from the 'King of Clay,' and was in a state of emotion as he was taken off the court in a wheelchair.

On that occasion, the two competed for over three hours as Nadal won 7-6, 6-6 (ret). Speaking about the injury in the aftermath, Nadal said: "It's very tough and I'm very sad for him.

"He was having an unbelievable tournament and he's a very good colleague on the Tour. I know how much he's fighting to win a Grand Slam; in this moment he was very unlucky, and the only thing I'm sure of, is that he's not just going to win one [Grand Slam] but more than one. I wish him all the very best and very quick recovery."

Zverev has enjoyed a brilliant tournament, having never gone beyond the fourth round at SW19 before this year. The German, who has now played in the final of all four Grand Slams, has had a superb year, claiming his maiden major title at the French Open last month.