After a disastrous World Cup for Spain, goalkeeper Iker Casillas is now feeling the pressure to turn things around at Real Madrid.

Casillas appeared to be the target of jeers from some Madrid fans — while others chanted his name in support — during Madrid's 2-1 loss Saturday to crosstown rival Atletico Madrid.

The jeers started after Madrid had conceded a goal to Atletico midfielder Tiago Cardoso from a corner kick, when Casillas failed to attack a tight cross.

"If they (the fans) feel they need to jeer, then you have to accept it and keep working," said Casillas.

Once widely considered among the best goalkeepers in the world, Casillas' reputation was dealt a serious blow at the World Cup when Spain conceded seven goals in its opening two losses that meant an early end to its title defense.

Madrid has conceded a total of six goals in its last two league defeats and trails both defending champion Atletico and league leader Barcelona.

Casillas had only recovered his starting job at the club from Diego Lopez at the start of this season after losing it two seasons ago under former coach Jose Mourinho. Carlo Ancelotti made Casillas his starter in the Champions League and the Copa del Rey last season, with Madrid winning both titles.

Madrid sold Lopez this summer, but it signed Keylor Navas after his outstanding World Cup for Costa Rica. So if Casillas falters, Navas is waiting.