MADRID (AFP) - Barcelona's Brazilian international defender Sylvinho will miss the rest of the season after he injured his right knee during the club's 4-1 loss to Real Madrid, the Spanish club said Thursday.

The 34-year-old came on as a half-time substitute against the new Spanish champions during the match on Wednesday night but hobbled off the pitch just 14 minutes later after tackling Real wingback Marcelo.

He has apparently sprained an internal ligament in his right knee and could be out for one month, Barcelona's medical services said in a statement.

Real have 81 points after Wednesday's match, 10 more than Villarreal and 17 ahead of third-placed Barcelona with two games remaining.

Sylvinho joined Barcelona in 2004 after spending three seasons at Vigo. He said recently that he expects to sign a one-year contract extention with the Catalan side which would keep him with the club until June 2009.