Dani Alves ruled out of Brazil friendlies
Alves, 29, will miss Brazil's upcoming fixtures against Iraq and Japan on October 12 and 16.
A statement on Barcelona's official website said: "Dani Alves will be out of action for three weeks. The Brazilian picked up a hamstring injury in his left leg in the match against Real Madrid. Martín Montoya came on in his stead on the 27th minute."
The fullback is also likely to miss Barcelona's fixtures against Deportivo La Coruna and Rayo Vallecano.
Alves' Barcelona were held to a 2-2 draw by Real Madrid in last night's clash with both Lionel Messi and Cristiano Ronaldo scoring a brace each.
The Seleção fullback, who has won 58 caps for Brazil, was called up by Mano Menezes for the friendlies and has been a permanent fixture in the national side in recent years.