Conciliation service Acas is looking to pre-empt any potential employer versus employee rows arising over World Cup issues by giving advice on its website.
England fans will be hoping not to miss their World Cup matches
It offers help on issues from access to TVs for staff during working hours, to what bosses can do about any pattern of "sickies" arising during the event.
Acas chief John Taylor said there were "very tricky issues to tackle".
The CBI and the TUC have already aired disagreements on whether workers were likely to stay home to watch matches.
Last month, CBI deputy director general John Cridland said many firms were worried about staff skipping work to watch England's World Cup football matches.
TUC general secretary Brendan Barber replied by saying that as England's fixtures were evening kick-offs, there were unlikely to be many football "sickies" taken.
England's group games take place either on weekday evenings or at weekends. Should they progress to the next round, this would also be a weekend fixture.
But there are supporters of many World Cup nationalities in the UK workplace, and many England fans may also spend nights in the pub watching other big matches.
"This is so serious a debate that we have had to issue a website page with frequently asked questions," said Mr Taylor.
"They cover everything from 'Does my employer have to provide me with access to the games if I am working?' to 'My employee has a history of taking sickies whenever there is an important game'."
He said employers should be "flexible wherever possible, to avoid discriminatory practices" and also "be aware we live in a diverse and multinational society, with a range of national games that people want to watch".
He added that if possible, workplaces should provide a rest area with a television screen, so that individuals could use their breaks to watch the match.
Staff should also be made aware of any restrictive policies already in place, dealing with issues such as absence, internet access and drugs and alcohol in the workplace, he said.
"We want to avoid trouble, reward good behaviour and allow Acas and its staff to have a more enjoyable time during the games as well," Mr Taylor said.