The duo occupy two of the three relegation spots with Almeria currently only above Vallecano due to a superior goal difference, while Real Valladolid - fresh from stunning champions Barcelona - also have 26 points and remain mired in relegation trouble in 17th.
Vallecano may be fighting to stave off the threat of the drop, but they head into Saturday's encounter at the Estadio del Rayo Vallecano in promising form.
Paco Jemez's men have won three of their last five league matches, including a spirited 3-2 victory at Real Sociedad on Monday, which followed a 1-0 success over Valencia.
Speaking to the club's official website, he said: "After taking six points against Valencia and Real (Sociedad) that can be worth a lot, now we have to fight with the teams that are down. Now is when we depend on us more than ever."
In contrast to Valladolid's upturn, Almeria's past four games have yielded just a solitary point and their defence has been breached seven times in the last two Liga fixtures.
However, Valladolid meet a Sevilla side that has recorded three Liga victories on the spin and another three points would boost hopes of European qualification.
Real Betis' chances of staying up are increasingly slim, although they visit fellow strugglers Elche on the back of a morale-boosting 2-0 win over Getafe.
Osasuna are also in danger and travel to Camp Nou to face Barcelona at possibly the worst time, as Gerardo Martino's men will be desperate to avenge the Valladolid setback.
Carlo Ancelotti's Real side, who are on a 17-match unbeaten run in the league, will attempt to firm their grasp on top spot at Malaga, while Atleti's challenge continues when they host Espanyol at Vicente Calderon.
