The defeat was Barcelona's first in their Nou Camp stadium in any competition this season and prompted questions over the European champions' ability to win La Liga for the third consecutive year.

"Maybe we are not at the level we were at last year," admitted Barcelona's Mexican international defender Rafa Marquez.

Critics have pointed to the slump in form of 2004 and 2005 World Player of the Year Ronaldinho who was subjected to jeers from Barca fans after Wednesday's loss.

Nevertheless, Barcelona are still in pole position by a point and in the last 16 of the Champions League once again.

"Barcelona aren't as bad as everyone says," said Osasuna midfielder Raul Garcia.

"It's clear that they are not having some of their best games but they are always a difficult rival. They are still the league leaders."

However, the Pamplona-based side are quietly optimistic that they can make life difficult for Barca.

Last season, they were one of the few teams to defeat the champions, beating them 2-1 in their intimidating Reyno de Navarra stadium en-route to finishing fourth.

However, this season, Osasuna have been more erratic and currently lie 10th.

One slight problem for Osasuna coach Jose Antonio Ziganda is that defender Josetxo Romero and striker Roberto Soldado are both suspended.

Sevilla lie second but coach Juande Ramos will take stock of his options for Sunday's match against struggling Real Sociedad in the wake of the Cup derby against Real Betis on Thursday.

Real Madrid are in third place, four points behind Barcelona, and will be looking to keep up the pressure by beating relegation-threatened Levante on Sunday.

Coach Fabio Capello will be relieved that club captain Raul Gonzalez, Jose Antonio Reyes and Emerson have all recovered from injuries and trained with the rest of the team on Thursday.

With Ronaldo now having signed for Milan, there is a strong possibility that Raul will play up front alongside Ruud van Nistelrooy.

Sergio Ramos and Fernando Gago were still training lightly on their own on Thursday, recovering from knocks suffered in the 1-0 loss at Villarreal last Saturday, but club officials said they were optimistic that they would also be fit to play against their visitors from Valencia.

"We are still in contention in the league and still in the Champions League. I don't see why we can't win both titles," said Gago.

Meanwhile, a degree of calm has returned to Real with Spanish judges throwing out a legal challenge to last summer's presidential elections on Thursday, leaving the incumbent Ramon Calderon to continue as president.
Fixtures
(Kick-off times in GMT)
Saturday
Deportivo La Coruna v Real Mallorca (1900), Espanyol v Real Zaragoza (1900), Valencia v Atletico Madrid (2100)
Sunday
Athletic Bilbao v Real Betis (1600), Celta Vigo v Gimnastic Tarragona (1600), Racing Santander v Getafe (1600), Recreativo Huelva v Villarreal (1600), Sevilla v Real Sociedad (1600), Real Madrid v Levante (1800), Osasuna v Barcelona (2000)