Both sides are on 31 points in the table, with Barcelona in fourth and Atletico third, while the capital outfit also have a game in hand on 18 of the other 19 teams in the division.
Barcelona picked up an enormous result in the Champions League on Tuesday evening, recording a 2-1 victory over Porto to secure their spot in the last-16 stage of the competition, and the fact that they had to come from behind against the Portuguese giants made it an even bigger win.
Xavi has managed to lead the Catalan side into the last-16 stage of the European Cup for the first time since his arrival as head coach, and he will now be focusing on La Liga, with the team looking to return to winning ways following their 1-1 draw with Rayo Vallecano last weekend.
Barcelona lost 2-1 at home to Real Madrid in the league at the end of October and were then unconvincing in wins over Real Sociedad and Alaves, before being held by Rayo last time out, and there has been pressure on head coach Xavi due to some underwhelming performances and results.
The reigning La Liga champions are currently fourth in the table, level on points (31) with third-placed Atletico, boasting a record of nine wins, four draws and one defeat from 14 matches, while they sit four points off division leaders Real Madrid.
The Catalan team have won their last three league games against Atletico, including a 1-0 success in the corresponding match last season, while they have not lost a home fixture in Spain's top flight to the Red and Whites since February 2006, which is an indication of the capital team's task here.
The fact that this match is not taking place at Camp Nou could potentially take away the home advantage, though, with Atletico instead heading to Estadi Olimpic Lluis Companys, which is Barcelona's home while Camp Nou undergoes renovation works.
Diego Simeone's side will enter this match off the back of four straight wins in all competitions, including a 1-0 success over Mallorca in La Liga last weekend, with the result moving them onto 31 points, boasting a record of 10 wins, one draw and two defeats this season.
Crucially, Atletico also have a game in hand, as their fixture with Sevilla, scheduled for the start of September, had to be postponed due to bad weather, so they are four points off the summit with a game in hand, which puts them firmly in a title race at this stage of proceedings.
The Red and Whites were in Champions League action on Tuesday evening, recording a 3-1 victory over Feyenoord in the Netherlands, with the result securing their spot in the last-16 stage of the competition, and they will go head-to-head with Lazio later this month for top spot.
Atletico have scored more goals (30) than Barcelona (27) in La Liga this season and have also conceded fewer, shipping 12 to Barcelona's 14, and they will head into Sunday's fixture full of confidence against a side that have been underwhelming in the league of late.
Barcelona will again be without number one goalkeeper Marc-Andre ter Stegen, who has not been able to play since suffering a back injury during the international break with Germany.
Ter Stegen is yet to overcome the issue, so Inaki Pena will again be given the nod between the sticks, with Xavi potentially selecting the same XI that started against Porto.
Alejandro Balde could miss out on a spot once again, with Joao Cancelo potentially being shifted across to left-back, while Joao Felix is allowed to play against his parent club, so the Portugal international is likely to be in a front three with Robert Lewandowski and Raphinha.
There are also not expected to be any changes to the midfield, with Pedri, Ilkay Gundogan and fit-again Frenkie de Jong set to line up in the middle, with Gavi out for the season due to an ACL injury.
As for Atletico, Pablo Barrios has suffered a serious knee injury, with the midfielder now expected to be unavailable for selection for at least the next three months.
Barcelona possible starting lineup:
Pena; Araujo, Kounde, I Martinez, Cancelo; Pedri, Gundogan, De Jong; Raphinha, Lewandowski, Felix
Atletico Madrid possible starting lineup:
Oblak; Gimenez, Witsel, Hermoso; Molina, De Paul, Saul, Koke, Riquelme; Morata, Griezmann
We say: Barcelona 1-1 Atletico Madrid
This has all of the makings of a fascinating match, and we are expecting a close game on Sunday. There has not actually been a league draw between these two sides since May 2021, but we are finding it difficult to separate them and have therefore had to settle on a 1-1 here.
For data analysis of the most likely results, scorelines and more for this match please click here.