Sunderland head coach Lee Johnson has warned against the use of snus in football, which he likened to smoking three or four cigarettes at once.
Snus is a smokeless oral tobacco product originating in Sweden made from ground or pulverised leaves, packaged similar to a teabag sachet which is placed under the top lip.
While possession and use of snus is not illegal, since 1992 it has been banned from sale in the UK and European Union, apart from in Sweden, under current regulations.
Even with no smoke inhaled, Johnson maintains the impact can be just as detrimental on both a player's physical health and mental well-being.
"It gives you that sort of buzz. I have not tried it myself, but having spoken to the players, the worry for me is it is so highly addictive," Johnson said on Talksport.
"I have had players who are so highly addicted that they are in hospital overnight with something else, maybe an operation, and are begging the doctors and nurses to get them a tub – or otherwise they say they are going to run out of bed and get it themselves when they have just had a knee operation.
"It is almost part of the footballer's starter pack now – it is in the washbag, the little tubs of snus"
"It is so highly addictive that it comes to the forefront of our minds which then becomes dangerous."
Johnson, who started his playing career at Brighton before lengthy spells at Yeovil and Bristol City, is concerned about what the lasting impact of repeated snus use could be.
"You are messing with the balance of the body and mind, that is the biggest thing for me in terms of development," he said.
"You will find that some players have two or three snus sachets under their lip, but then they are taking caffeine tablets, so it is giving themselves that calming effect.
"They are then going into a game trying to lift themselves and are therefore taking caffeine tablets or Red Bull to try to get the boost.
"(With) so many spikes in the body, sort of balance if you like, I don’t believe it is conducive to top performance, but more important it is not conducive to the player being healthy for a long period of time.
"It is nicotine going into the body and an awful lot of it.
"I see how many players are actually on it – you could probably go to maybe a third or half of a dressing room. I think they are uneducated on the negatives towards it."
Johnson added: "I have seen it when I was playing myself, and I have seen the effect it had in both performance and also health of the players I have played with.
"It is almost part of the footballer’s starter pack now – it is in the washbag, the little tubs of snus.
"Sometimes players can have three or four under their top lip at one time and it is effectively the equivalent of smoking three or four cigarettes at one time."