Primera Liga matches, April 17-18

Injury problems could force Real Madrid coach Carlos Queiroz to remodel his much-maligned defence as the team attempt to restore their shattered morale with a win against city rivals Atletico Madrid on Saturday (2000 GMT).

Centre backs Ivan Helguera and Alvaro Mejia are struggling with minor niggles, while Brazilian full back Roberto Carlos faces a late fitness test on an injured toe.

A miserable run of form in the last month has meant Real lost the Spanish Cup final to underdogs Real Zaragoza, tumbled out of the Champions League against unfancied Monaco and frittered away an eight-point lead at the top of the table.

With just six games to play, the champions trail in-form Valencia by two points after last weekend's humiliating 3-0 home defeat to Osasuna, but the players remain hopeful that they can turn the tables on the leaders.

"We want to end our poor run this weekend and make sure we are back fighting for the title," Real skipper Raul said on Thursday. "We know that after Osasuna we must win this one so that we can keep the pressure on Valencia."

Real prepared for the local derby with a three-day training camp in the luxury resort of La Manga in the south of Spain, where their daily sessions were watched by over 1,000 fans.

But they will be assured of a more hostile reception when they make the short hop across the city to meet Atletico, who are still hoping to secure a place in next season's UEFA Cup.

Both sides will be without their leading strikers for Saturday's clash.

Ronaldo, who has scored 24 league goals for Real this season, has been ruled out because of a thigh strain, while Fernando Torres, who has notched 15 for Atletico, is suspended after his sending off in last week's 3-1 defeat against Malaga.

Other matches being played this weekend (standings in brackets; kickoff times 1530 GMT unless stated):

Saturday:

ATHLETIC BILBAO (6) REAL ZARAGOZA (13) 1800

Bilbao hung on to a UEFA Cup berth after last week's last-gasp win away to Racing Santander, but they face a tougher task against Cup winners Zaragoza who have only lost once in their last eight outings.

Influential winger Joseba Etxeberria has recovered from a leg strain, but keeper Daniel Aranzubia is out of action.

DEPORTIVO CORUNA (3) VALLADOLID (16) 1600

Depor coach Javier Irureta may choose to rest several of his first-choice players ahead of next week's Champions League semi-final against Porto, but he will be anxious not to undermine his side's title chances by making too many changes.

Valladolid are still not clear of the danger zone and are certain to make for tricky opponents.

Sunday:

ALBACETE (15) CELTA VIGO (19)

Celta must win this one if they are to give themselves a realistic chance of avoiding the drop. The Galicians, who have not won in eight games, will be without the injured Peter Luccin and Vagner and fellow midfielder Jose Ignacio who is suspended.

BARCELONA (4) MALAGA (8) 1930

Despite extending their unbeaten run to 14 matches, Barca look to have waved goodbye to their slim hopes of snatching the title after their 1-1 draw at Betis in midweek.

Ronaldinho is back after serving a one-match suspension and influential full back Carles Puyol returns from injury. Turkish international keeper Rustu Recber should get a rare start after Victor Valdes's dismissal in the Betis match.

MURCIA (20) REAL BETIS (11)

Even if they win, John Toshack's Murcia will still find themselves relegated this weekend if fellow strugglers Mallorca beat Villarreal.

Mid-table Betis, who have not won in eight games, have little to play for now that their hopes of earning a European place have evaporated.

OSASUNA (5) ESPANYOL (18)

Osasuna coach Javier Aguirre has done a brilliant job with the modest Navarrans this season and he gave a tactical masterclass as his side exploited Real Madrid's defensive weaknesses to inflict a 3-0 defeat on the champions last week.

Espanyol need a win if they are to avoid the drop.

REAL MALLORCA (17) VILLARREAL (10)

Villarreal will be on a high after their brilliant midweek victory over Celtic earned them a place in the semi-finals of the UEFA Cup, but they are unlikely to receive any congratulations from Mallorca who are still not clear of danger despite last week's morale-boosting victory over Betis.

SEVILLA (9) RACING SANTANDER (14)

Sevilla need to win this one if they are to keep their UEFA Cup options open. Striker Dario Silva is fit again, but midfielder Francisco Gallardo is suspended. Israeli forward Yossi Benayoun and defender Jose Moraton are doubtful for Racing, while centre back Juanma is suspended.

VALENCIA (1) REAL SOCIEDAD (12) 1730

Valencia knocked Real Madrid off top spot last weekend after notching up their sixth win in a row, a patient 1-0 victory at Zaragoza. They then completed a perfect week by earning their place in the semi-finals of the UEFA Cup with a comfortable 4-2 aggregate victory over Bordeaux.

But Rafa Benitez's side can not afford to rest on their laurels if they want to maintain their bid for an historic domestic and European double.

Argentine playmaker Pablo Aimar is still out with a groin injury and defender Curro Torres is serving a one-match ban. Sociedad striker Darko Kovacevic is also suspended.