The Brazilian has failed to shake off a muscle strain and joins Lionel Messi, Deco, Giovani Dos Santos, Santi Ezquerro, Rafael Marquez and Yaya Toure on the sidelines.

The absence of those players leaves coach Frank Rijkaard with huge selection problems in attack and midfield ahead of Sunday's game.

With Ronaldinho, Messi and Giovani all missing, Rijkaard looks set to keep faith with under-fire strikers Thierry Henry and Samuel Eto'o, who were both disappointing in last week's home defeat against Villarreal.

Following that match, Villarreal winger Robert Pires suggested Barcelona should ditch their habitual 4-3-3 formation in favour of a more competitive 4-4-2.

But Rijkaard says he will keep faith with his favourite formation.

"The system works and we have no reason to change it," he said on Saturday.

Andres Iniesta could therefore be moved into a more attacking role on the left of the team's three-pronged attack, while Bojan Krkic is another option for Rijkaard.

Midfield is also a problem as the team's two recognised holding midfielders - Toure and Marquez - both sit out through injury.

Their absence is likely to mean a rare start for Edmilson, while Eidur Gudjohnsen looks set to come in for the injured Deco.

Despite so many key absences, Rijkaard believes his side can secure an important win in Almeria.

"The players available have worked with enthusiasm and desire, and we are going to fight for a positive result in this match until the last moment, despite the absences," he said.

Almeria have a good record at the Nuevo Mediterraneo - where they beat Real Madrid last month - and Rijkaard is expecting a difficult match on Sunday.

"It's a difficult ground to go to. They are a good team who normally play well at home, but we are highly motivated and want to show that," he said.

Barcelona closed to within two points of leaders Real Madrid just three weeks ago, but back-to-back defeats to Atletico Madrid and Villarreal have seen the Catalans slip off the pace once again.

Rijkaard's side are now eight points adrift of Real, but the Dutch coach does not believe recent disappointments mean there is now more pressure on his team.

"The pressure is the same. There is always pressure here, because that's the philosophy of Barca," he said.

Almeria went unbeaten in their first six Primera Liga matches after Christmas, but have now picked up just one point in their last three games.

However, they remain in eighth place and coach Unai Emery says his team are aiming for victory on Sunday.

"We will go there with a winning mentality and to win the three points, which are very important," he said on Saturday.

Emery believes Barcelona will be dangerous, despite their many absentees.

"Barcelona are one of the biggest teams in international football, and even with players out their potential is still at its maximum level because their squad is like a world selection," he said.

Bruno Saltor misses out through injury, but Santiago Acasiete could return and Juanma Ortiz is back from suspension.