Talks were ongoing for several months between the DBU and the players' union over a new contract for players called up to the national team, though on Friday night the DBU reportedly walked out of the negotiations.
Denmark are set to play Slovakia in a friendly before a Nations League match against Wales, with the squad announcement to come shortly. However, an agreement is yet to take place between the DBU and the players.
As a result, Denmark may have to call up an entirely domestic based squad, while if they are forced to forfeit the game with Wales then a UEFA ban is extremely likely.
The DBU have had a similar disagreement with the women's national team, which resulted in a World Cup qualifier being cancelled and the DBU being fined and warned about future expulsion if it happened again.
One of Denmark's most experienced players, Simon Kjaer, has blamed the DBU for the stalemate.
Speaking to Danish newspaper 'Ekstra Bladet', he said: "It is the DBU that creates problems and risks for cancelled international matches and giant consequences for everyone in Danish football.
"We feel that the DBU would like to make us mad. They will make it as if it's us players who do not want to play internationally. But that's exactly the opposite.
"I must admit that it is our clear impression that the DBU has not been interested in finding a quick solution. Right now we fear the consequences for Danish football."