FANS have spotted something unusual about Cristiano Ronaldo’s latest picture.

The 38-year-old took to the sauna in his Instagram story as he looked to enjoy some downtime after a busy week in Saudi Arabia.

Ronaldo has been enjoying life in Saudi Arabia since leaving Man United last year. Credit: AFP

Ronaldo’s painted toe nails caught the eye on social media. Credit: Instagram

Ronaldo showed off his ripped physique in the snap but the attention of fans was drawn to something other than the star’s abs.

They quickly noticed that Ronaldo appeared to have his toenails painted black.

It is not the first time the Al Nassr forward has done this either, with followers also drawn to his feet when he was pictured with UFC fighter Francis Ngannou earlier this year.

Fans registered their surprise at Ronaldo’s sauna picture on Twitter.

One said: “Did I miss something or everyone else missed it. Did Ronaldo paint his toe nails?”

While another said: “All I know is athletes who do MMA usually add paint to get a protective layer or something.”

A source appeared to confirm this theory to German publication Bild.

They said: “Many top athletes do this to protect their nails from fungi and bacteria when they are stuck in sweaty shoes for hours. Even Mike Tyson.”

Ronaldo has been in fine form since making the switch to Saudi Arabia at the turn of the year.

He has 11 goals in 10 league matches and now trails the Saudi Pro League’s top scorer Odion Ighalo, the ex-Watford striker, by just five goals.

But it has not all been plain-sailing with the Al-Nassr manager Rudi Garcia sacked last week.

The head coach reportedly clashed with first team players before being given his marching orders.

Al Nassr sit second in the Saudi Pro League, three points behind leaders Al-Ittihad.