The forward could also miss the start of Brazil's World Cup qualifying campaign, having been substituted after 15 minutes. Real face Getafe on September 2 while Brazil host Bolivia six days later before travelling to Peru on September 12.

However, Ancelotti said the injury was not serious, unlike those suffered by goalkeeper Thibaut Courtois and defender Eder Militao earlier this season, and he was confident Vinicius would recover in time to return after the international break.

"Vinicius has had some muscle discomfort in his leg. It wasn't a very serious thing. He tried to play but it was bothering him and we preferred to sub him," the Italian told reporters.

It is the first muscle injury suffered by the left winger, who has scored 28 goals with 19 assists for Real since the start of last season.

Ancelotti added that Real will not look for further signings as his squad is strong enough despite injuries and the departure of Ballon d'Or winner Karim Benzema to the Saudi Pro League.

"It is a complete squad. If we are able to win without Courtois, Militao, Karim, Vinicius, it means that the squad is well put together. They have done well," he said.

Leaders Real have had a perfect start to LaLiga with three wins in three games.