Barcelona and Brazil star Ronaldinho is likely to be out of action for five weeks after pulling a right leg muscle in Sunday's 2-1 home win over Betis, the Spanish club's medical staff said Monday.

The injury means he could miss two World Cup qualifiers and a crucial home league game in the first week of December against Real Madrid.

As well as being sidelined for up to four league matches and at least one UEFA Cup game Ronaldinho will also miss out on World Cup qualifiers away to Peru in November on Sunday and at home to Uruguay in Curitiba three days later.

The Brazilian suffered the injury challenging for a ball with visiting defender Luis Fernandez in the 14th minute of the win at the Nou Camp, Mexican defender Rafael Marquez notching the winner eight minutes from time with Dutch veteran Patrick Kluivert also on the scoresheet to break his league duck.

Kluivert came on for Ronaldinho, who initially tried to play on.

Barca doctor Lluis Til said an x-ray on the injury had shown up a five-centimetre (two-inch) tear in the femoral biceps of his right leg.

Barcelona stand fourth in the Liga but trail leaders Deportivo La Coruna by six points.