Barcelona's disjointed defense will have to find a way to stop Radamel Falcao when Atletico Madrid visits the Camp Nou on Saturday, while Real Madrid will be looking to recover from its worst league run under Jose Mourinho against Rayo Vallecano.
And while the big two look to bounce back from midweek draws, six Spanish league teams vie for a first win from five games - including Marcelo Bielsa's Athletic Bilbao, which plays against Villarreal. Getafe takes on surprise leader Real Betis, the only team to have won all four games this season.
Several coaches are already under pressure to turn their winless team's seasons around, including Mallorca's Michael Laudrup against Real Sociedad and Sporting Gijon's Manolo Preciado against Racing Santander.
Atletico won its last two matches by a combined 8-0 scoreline, with Falcao scoring five goals to put him among the league leaders alongside Lionel Messi and Roberto Soldado of Valencia. Barcelona's backline has struggled in recent games, with Gerard Pique missing and Carles Puyol still not 100 percent, and the Colombia striker is expected to offer the defending champion's defense its toughest test yet.
"I said it would be very difficult to replace (Sergio Aguero) and (Diego) Forlan but it looks as if Falcao has done it well,'' Atletico coach Gregorio Manzano said of the former Porto star, who set a record for goals in the UEFA Cup-Europa League competition last season. "He's a phenomenon.''
Atletico may be without fellow newcomer Diego in midfield, while Barcelona's already brittle midfield lost Ibrahim Affelay to a knee injury Thursday. The Catalans are already without Andres Iniesta and Alexis Sanchez, but Messi and Cesc Fabregas have carried the attack with nine goals.
Madrid, meanwhile, is off to its worst start since the 2005-06 season after a draw and a loss in its last two games.
The club is already without defenders Pepe and Fabio Coentrao and may lose Ricardo Carvalho for the match because of an injury sustained in Wednesday's 0-0 draw at Santander.
"It's not a crisis we just haven't played well this last week. It's easier to motivate players after negative results,'' Mourinho said Friday. "Some people are happy with the situation but I think that happiness will come to an end tomorrow.''
Madrid is still only one point behind fourth-place Barcelona, which in turn trails leader Betis by four. Valencia is second, two points behind.
Getafe coach Luis Garcia is also under pressure to turn the Madrid club's fortunes around, just like Laudrup, who has led the Mallorca to one victory and four defeats.
"These have been turbulent moments but that's all part of football,'' Laudrup said after Tuesday's 2-0 loss at Villarreal, the club's third straight defeat. "We can't talk about the future because we don't know what will happen in the next month. We have to keep working, there's no other way to get there.''
The club's attack has dropped off following the departure of striker Pierre Webo and midfielder Jonathan De Guzman, who scored the winner in the team's lone victory of the season before being sold to Villarreal.
Preciado may be the longest serving topflight coach - he's been in charge since 2006 - but, like Mallorca, his team has failed to generate much of an attack and is expected to be involved in the fight to avoid relegation.
Bilbao was expected to challenge for a European spot but may have to lower its goals after a third straight loss.
Valencia held Barcelona to a 2-2 draw but knows it must pick up points away from the Mestalla as well to have any chance of challenging for the title, starting with Saturday's game at Sevilla.
"It's true it's been a tough start to the season for the big two which has given us a little chance to play with them,'' Valencia winger Jeremy Mathieu said, "so we'll see what happens from here.''
In other games, it's: Levante vs. Espanyol; Granada vs. Osasuna; and Zaragoza vs. Malaga.
