The Celtics forward tore his left knee while playing for Italy in a World Cup qualification game.
The Italian team said that he would not be able to play in the EuroBasket tournament because of his injury.
The player grabbed his knee after a bounce pass in the lane. He hobbled over to the sideline, holding the back of the knee as trainers rushed to his aid, before limping to the locker room.
Italy captain Luigi Datome said it was difficult to talk about basketball after seeing what happened to Danilo. We wish him good luck.
As Boston looks to return to the NBA Finals, it was important for the Celtics to have a player like Gallinari on their roster.
A first-round draft pick of the New York Knicks in 2008, Gallinari has played for five different teams in his career.