Josko Gvardiol has been one of a number of players wearing a mask in Qatar (Picture: Simon Bruty/Anychance/Getty Images)

Much has been unusual about the World Cup, from the tournament taking place for the first time in winter, to the generous amounts of stoppage time added on at the end of halves.

And another weird sight at Qatar 2022 has been football players wearing black face masks whilst taking part in games.

With Croatian defender Josko Gvardiol set to sport one during the semi-final clash with Argentina, many fans will once again be asking the question – what on Earth are they for?

Read on for everything you need to know.

Why do footballers wear black masks at the World Cup?

The masks are worn by footballers who have suffered an injury to their face in a previous match.

Gvardiol has excelled in Qatar despite his injury (Picture: Youssef Loulidi/Fantasista/Getty Images)

The structure is specifically designed to protect the area of face from direct impact by absorbing the energy from contact with other players.

They are thought to be made of carbon fibre, which is an extremely light yet incredibly strong material, and they can be personalised to fit around the contours of an individual’s face.

The protective masks are deemed ‘non-dangerous protective equipment’ by the International Football Association Board, and as such they are legally allowed to be worn by players.

Gvardiol is wearing a face mask against Argentina after breaking his nose in a collision with teammate Willi Orban during Leipzig’s 3-1 win over Freiburg on November 9.

The Leipzig and Croatian medical teams determined that the only way Gvardiol could feature in Qatar was by wearing the mask.

Son Heung-Min looked a little different playing for South Korea (Picture: Patrick Smith – FIFA/FIFA via Getty Images)

South Korea’s Son Heung-Min also wore a mask during their World Cup fixtures after fracturing his eye socket during Tottenham’s Champions League match with Marseille on November 1.

Speaking about his new gear, Son said: ‘I don’t think it was bad because the mask was more comfortable than I thought.

‘In fact, it was a little different from when I used it in England. It was more comfortable. Except for sweating a lot because the weather was hot, there was no big difference.

More: World Cup 2022

‘The reason I keep touching the mask is because the shape of my face is slightly different. Even if the swelling goes down, one day it’s still swollen. I keep touching it after fitting it to my face. I was surprised that it was a lot more comfortable than I thought.’

The 30 year-old added: ‘It’s made of good material. It’s light, hard when worn on the face, and it’s a good material that can protect against impact. I was surprised that it was considerably lighter than I thought.’

Tunisia’s Ellyes Skhiri also donned a black mask during the World Cup after fracturing his cheekbone playing for FC Koln in October.

MORE : Argentina vs Croatia: Who is World Cup referee Daniele Orsato?

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It’s an unusual look.