If you've been paying close attention to Germany at Euro 2020, you'll have noticed that their defender Antonio Rudiger is wearing a mask while he plays.
It's not a tribute to Batman, or even to Robin, nor is it a fashion statement, so what exactly is the Chelsea centre-back got it on his face during games?
In case you've been wondering what it's for, Goal brings you all you need to know.
Why is Antonio Rudiger wearing a face mask?
The face mask worn by Antonio Rudiger during games is a protective one designed to shield his facial bones and minimise the risk of further injury.
Rudiger first sustained a blow to his face during the first leg of Chelsea's Champions League semi-final clash against Real Madrid on April 27.
"He has a little bone injury on the side of the face," explained Chelsea boss Thomas Tuchel at the time. "The collision [with Alvaro Odriozola] at the very end of the game was a bit unlucky."
Since then, Rudiger has played games with a face mask as a protective measure and has continued to do so into June while playing for Germany at the European Championship.
The reason for the continuation of the mask is that Rudiger believes his national team will have to get stuck in if they want to beat the best.
"It’s still there for protection," said the no-nonsense 28-year-old ahead of Germany's meeting with France. "I’ll have to see what the Chelsea doctors say when I get back to London."
He added: "We have to be a little dirty, not always be nice or try to play nice football. Against players like them, you have to throw down a marker."
Rudiger confirms on the #CFC app that he broke his jaw against Real Madrid a few weeks ago. A real warrior and leader in the mask for Chelsea at the moment. #MCICHE
— Nizaar Kinsella (@NizaarKinsella) May 8, 2021
Tuchel indicated that it was a "little bone injury" but Rudiger later confirmed that he had suffered a broken jaw when he collided with Odriozola.
Protective face masks such as the one worn by Rudiger can also be used in cases where players have broken other bones in their face, such as the nose, cheek or orbital.
The defender is by no means the only footballer to have donned a face mask while playing and, interestingly, a number of Chelsea stars have had to do so in the past.
Cesc Fabregas wore one after having his nose broken during a game against Stoke City, while Cesar Azpilicueta had to put one on for a while after hurting his cheekbone in a game against Crystal Palace.
Midfielder Nemanja Matic wore a face mask for a number of games at Chelsea, as did John Terry, Ramires and Fernando Torres, so Rudiger is following a well-worn tradition at Stamford Bridge.
The nature of Rudiger's role as a defender, where he is likely to be challenging for headers and putting his body in front of goal-bound shots, means that a protective mask is a wise accesssory to have.
Can you buy face guards & how much do they cost?
Face guards such as the one that Rudiger wears can be bought online or sourced through medical supplies shops like pharmacies.
While not commonly worn in football, they are worn more often by athletes in sports where there is a higher likelihood of a facial injury while playing.
They can cost in the region of £60 or $60 and you should consult your doctor or a medical professional before using one.