Lionel Messi and Javier Mascherano were pictured on the big screen at the match between the Washington Wizards and the Indiana Pacers.
The Argentine national squad, who will play a friendly against El Salvador in Washington, were invited to watch the basketball game beforehand. Their presence caused excitement among the crowd.
Messi posted a picture of himself at the game on the social networks, saying "Watching the NBA".
After the game finished, with the Washington Wizards winning, Messi and Mascherano, along with their team-mates, were photographed with various NBA representatives, including their compatriot Luis Scola, and Messi received a gift - a Wizards shirt.
Watch the Barcelona stars at the game here: