"Barcelona could be on their way to being champions. If they carry on playing like this, no one is going to catch them," said Atletico's Spanish international striker Fernando Torres.

"Everyone thought they were wobbling but they shut a lot of mouths with their 4-0 win at Sevilla last week."

The big worry for Barca coach Frank Rijkaard is that his inspirational Brazilian midfielder Ronaldinho has missed training all week.

The World Player of the Year picked up a leg injury in last weekend's match.

French international Ludovic Guily is another who will have a late fitness test after suffering again from his chronic back problems, working out for several days alongside Ronaldinho in the Barca club gym.

Atletico have their own injury problems though, with both Jose Antonio Garcia Calvo and Jesper Gronkjaer both doubtful.

Barcelona have 51 point from their 21 games and a seven point advantage over bitter rivals Real Madrid, who play host to fourth-placed Espanyol on Saturday.

Pundits have been quick to point out this week that the visit of the Barcelona-based club means the season has turned full circle for Real.

It was Espanyol's 1-0 defeat of the Spanish giants in September that precipitated the resignation of former Spain boss Jose Antonio Camacho.

Mariano Garcia Remon then took over as the Real coach only, in turn, to be superseded by Wanderley Luxemburgo during the winter break.

However, Luxemburgo has cured Real's woes as the team has rattled off five consecutive league wins since his arrival.

The encounter will see two old friends come face-to-face as foes.

Espanyol playmaker Ivan De La Pena and Real's Ronaldo played together at Barcelona during the 1996-97 season and are still regularly in close contact.

"I used to have great fun playing alongside Ronaldo," said De La Pena. "He was a bit thinner then, but he's still a phenomenon on the pitch."

The main worry for Luxemburgo is whether Zinedine Zidane will recover from his midweek bout of gastro-enteritis.

If Zidane is unfit, Spanish international Jose Maria Gutierrez will start alongside recent signing Thomas Gravesen.

Reigning champions Valencia are now a distant third behind the top two, having only managed two points from their last three games to fall seven points behind Real Madrid.

The sorry streak prompted an astonishing outburst from Valencia coach Claudio Ranieri during training on Wednesday.

"Why do you only react when you are up to your necks in trouble?" demanded Ranieri ahead of Sunday's match with Real Sociedad.

FIXTURES
Saturday (kick off times in GMT): Real Sociedad v Valencia (1900), Real Madrid v Espanyol (2100)

Sunday: Albacete v Real Zaragoza (1600), Real Betis v Osasuna (1600), Getafe v Numancia (1600), Levante v Sevilla (1600), Malaga v Real Mallorca (1600), Villarreal v Racing Santander (1600), Deportivo v Athletic Bilbao (1800), Barcelona v Atletico Madrid (2000)