A late penalty cost Barça two points as they failed to capitalise on Atletico's loss on Saturday
Barcelona missed the chance to make a dent in Atletico Madrid's lead at the top of the table as they were held to a 1-1 draw by Cadiz at Camp Nou on Sunday.
Alex Fernandez's late penalty earned the visitors a point, cancelling out Lionel Messi's first-half spot kick.
A win would have moved Ronald Koeman's side within six points of Atletico but instead they are eight points behind the leaders and five behind Real Madrid, although Los Blancos have played a game more.
Barca play again on Wednesday at home to Elche and can move within two points of Madrid and five of Atletico, although Diego Simeone's men will have a game in hand.
Sunday's game represented a chance to bounce back from the midweek loss to Paris Saint-Germain and Koeman picked an unchanged side, handing his players a chance to redeem themselves.
Against a deep Cadiz side, they enjoyed plenty of the ball early on but were largely restricted to half chances.
The opening goal arrived just after the half-hour mark when Pedri was quickest to react to a loose ball in the box, drawing in two opposition defenders and winning a penalty.
Messi, who passed Xavi Hernandez to become Barca's record-appearance holder in La Liga (506 games), scored from the spot to take his tally in the league this season to 16, level with Luis Suarez at the top of the scoring charts.
The goal didn't change the pattern of the game. Barca continued to see all of the ball and Cadiz continued to sit back.
The chances came and went. Messi and Ousmane Dembele ended the game with 14 shots between them, while Frenkie de Jong and Pedri both had goals ruled out for offside.
Cadiz created little in attack looked set to lose the game until Clement Lenglet's clumsy late challenge on Ruben Sobrino when there appeared to be little danger.
Fernandez, the brother of Real Madrid's Nacho, stepped up to covert from 12 yards, sending Marc-Andre ter Stegen the won way and earning Cadiz, the last team to beat Barca in La Liga, a point.