Fireworks in the early hours of Tuesday burst near the hotel where Argentina players are staying for their Copa América semifinal against host Brazil.
Three waves of fireworks were heard after 1:15 a.m. close to the team hotel in central Belo Horizonte.
Argentine media outlets also reported wake up calls were made to players' apartments at 6:30 a.m., without any of them asking for that.
Asked by The Associated Press about the incident, staff members of the Radisson Blu Savassi hotel said they can't provide information on their guests.
Dirty tricks like those are common in South America before key matches in World Cup qualifying and the Copa Libertadores.
Brazilian teams playing in Argentina have also had similar experiences.
On Monday, Brazil coach Tite told journalists he wants to win "with loyalty" and that "there can't be trickery" involved in the clash.
"Soccer transcends a few things, like the educational aspect. It doesn't solve social problems, but it has an educative intent," the coach said.
Brazilian fans also troubled the sleep of the Argentines with fireworks before the November 2016 World Cup qualifier in Belo Horizonte, where the host won 3-0.
The winner of the superclásico later Tuesday at Mineirão Stadium will face Chile or Peru in the final on Sunday at Maracanã Stadium in Rio de Janeiro.