Real Madrid and Barcelona will be looking to maintain their 100% starts to the Liga season when they face tough tests against Athletic Bilbao and Valencia on Sunday.
Madrid are first up when they host Athletic, who have also won both their opening matches, at the Santiago Bernabeu in the first midday kick-off of the new campaign.
Los Blancos have been made to wait to welcome Gareth Bale to the Spanish capital as his prolonged transfer from Tottenham Hotspur has dragged on for another week, but coach Carlo Ancelotti is more concerned with how those already at his disposal have performed so far.
Real have won both their matches against Real Betis and Granada by just the odd goal and the Italian is looking for an improvement against an Athletic side he rates highly.
"The match tomorrow isn't easy because Athletic have won their first two matches and have a very good and professional manager who I know well," he said on Saturday.
"Our objective is to start playing better. We want to play with intensity and I think tomorrow is just the moment to do so."
German midfielder Sami Khedira is available again after missing Monday night's win at Granada through injury and former Real Sociedad man Asier Illarramendi could make his Madrid debut as he also takes his place in Ancelotti's squad for the first time after a disrupted pre-season due to injury.
Ander Herrera meanwhile has been included by Athletic boss Ernesto Valverde in his squad despite Manchester United's interest in signing the midfielder before Monday's transfer deadline.
Like Madrid, Barcelona have also failed to shine since thrashing Levante 7-0 on the opening day of the campaign as they struggled to a 1-0 win over Malaga last weekend and then won the Spanish Super Cup against Atletico Madrid on away goals in midweek.
And coach Gerardo Martino is expecting another tough test when they visit the Mestalla on Sunday evening, despite their relatively good record there in recent times.
"Statistically we haven't lost their since 2006, but we have only won twice in that time," he said.
"They will go for it. They have good players that are always looking to attack. We need to try to limit (Ever) Banega because he could do us a lot of damage."
Martino has continued his policy of handing a rest to some of his stars by leaving Xavi Hernandez and Alexis Sanchez in the Catalan capital, but Lionel Messi and Adriano have both been included in the squad after being passed fit.
In Saturday night's action Celta Vigo continued their unbeaten start to the season, but will have been disappointed to drop two points after missing a host of chances in their 1-1 draw at home to Granada.
On-loan Barcelona midfielder Rafinha Alcantara put the hosts deservedly in front on the half-hour mark, but Piti levelled with his first Granada goal in the second half to ensure the points were shared.
Meanwhile, Valladolid secured their first win of the season as they beat Getafe 1-0 at home thanks to Marc Valiente's header early in the second-half.