Premier League managers have been told to warn their stars not to swear during games when the season resumes this week.It is understood League bosses fear a barrage of bad language could dominate matches that are being staged again behind closed doors.The likes of Pep Guardiola, Jose Mourinho and Jurgen Klopp will now urge their players to be aware of any profanities they use in the heat of battle.All stadiums will be virtually empty when the 92 remaining fixtures kick-off again on Wednesday in a bid to complete the season following the Covid-19 crisis.The matches will be shown live by a host of broadcasters and are expected to be watched by millions of people at home, including women and young children.TV cameras and microphones are likely.