Seeing footballers cover their mouths when speaking to a teammate or opponent on the pitch has become an increasingly common sight for spectators watching on TV or in a stadium.
It has always been assumed that this is done so that the sharing of tactical or private information can't be picked up by cameras with viewers potentially able to lip read secret conversations.
A famous example was when former Southampton winger Nathan Redmond covered his mouth when it appeared that Manchester City manager Pep Guardiola was shouting at the Englishman back in 2017.
The Saints had just lost 2-1 at the Etihad with a last-minute goal and the duo had a bizarre-looking conversation in which Redmond covered his mouth when responding.
Last night's game between Man City and Southampton was full of drama...— Soccer AM (@SoccerAM) November 30, 2017
A last minute winner ⚽
Mad celebrations 🙌
Plus an INTENSE full-time rant from Pep Guardiola to Nathan Redmond 😡😡 pic.twitter.com/FtjD1ac8HT
However, it turns out this has nothing to do with keeping information private but actually to do with making sure players can actually be heard.
Renowned PR consultant Phil Hall, who has worked with some of the biggest clubs and names in the Premier League, explained that no-one is being advised to cover up to protect vital team plans.
"A player once told me one of the main reasons they do it is, sometimes you are doing it when you are close to somebody, it amplifies your voice so they can hear you," Hall said.
"There is a lot of noise around them in a stadium and on the pitch, they need to amplify the voice.
"In a loud ground, when you speak normally the sound is being spread out.
"It's like a foghorn, if you put your hand over your mouth and point it to the person you are talking to it is much clearer."
He added: "It started in South America where a couple of TV stations hired guests to start reading what was being said on the benches and what was being said by the players.
"They employed lip readers and various methods to find out what was being said tactically by the bench to the players.
"But the players themselves over here, I think are just aping what they see on the continent. I don't think over here they are being actively advised to cover up.
"I have certainly not seen any evidence of lip reading over here, at any of the clubs I have done work with.