Tennis fans have expressed concern for Rafael Nadal after he showed off his slimmed down physique in a picture alongside Roger Federer.

The Spanish athlete was known for his muscular frame during his playing days but looked completely transformed as he shared the image to Instagram yesterday. 

While the post received much adulation from tennis fans, some were shocked by his body transformation. 

Nadal's aggressive and relentless playing style saw him win 22 Grand Slams - 14 of which came at the French Open - over a career spanning more than two decades.

But since retiring in November 2024, the 39-year-old hasn't needed to put his body through the training needed to be a professional athlete at the highest level - leaving fans in shock at his appearance. 

One fan said: 'Two LEGENDS like Nadal and Federer have been spotted by chance around Madrid.

'Keep an eye on how much weight Rafa has lost in recent months. He's turned into a real stick figure!!'

Another user remarked: 'Federer is still looking good, he turns 45 in a few months, he has looked after his body well over the years.

'Nadal unfortunately looks a bit gaunt and aged here he's still in his 30s, I just hope he hasn't done any long term health damage after his tennis career.'

Those two posts were on X and the sentiment was the same on Instagram among others.

'Nadal looks thinner, it seems like he's lost muscle mass and is even thinner than Federer,' said one account, while another posted: 'We need muscly Nadal back.'

Despite those comments, there were those who took a more positive view of Nadal's appearance - including Dan Wolken, a senior writer at Yahoo Sports.

'The comments under here are absurd,' he said. 'When someone retires from being a professional athlete, their body no longer looks like a professional athlete’s body because they are not spending all their time being a professional athlete. This isn’t complicated.'