15:15 GMT, Sunday 4th March, Camp Nou (Barcelona, Spain), Sky Sports
At the halfway point of this season's La Liga title chase, no one could have thought that the encounter between Barcelona and Atletico Madrid would be so crucial when it finally came around.
Of course, with the Blaugrana nine points ahead of Diego Simeone's team after 19 games, a title tilt from Los Colchoneros was not out of the question.
However, with an inability to take six points off Qarabag in the Champions League group stages, Atletico looked more likely than the league leaders to drop points in the second half of the season.
Instead, the returning Diego Costa has spurred his side on, reinvigorating a lacklustre Antoine Griezmann and bringing the Madrid-based side the sort of goal return that can match their frugality at the back.
The results this season speak for themselves. Atletico have only conceded more than one goal in a game on two occasions so far in the league and, with Costa scoring nine since rejoining the side in January, the second-placed Spanish side are now scoring with every 2.4 shots.
Barcelona, on the other hand, despite bolstering their attacking options, have struggled to get off the ground as an goal-scoring force in recent weeks.
A midweek draw to league strugglers Las Palmas reduced the game between Ernesto Valverde's side and their weekend opponents to five points, meaning that, by the end of this gameweek, the title race contenders could be separated by two points with an El Clasico fixture soon to come.
With all eyes on Serie A as the most exciting league challenge in the Big Five, this weekend could throw another division into the mix.
Last Time Out
Las Palmas 1-1 Barcelona (La Liga)
With the upcoming fixture already being intriguing enough, it was only going to be the case that this fixture would add to the drama.
An early indication that the night might not go in favour of the league leaders came early on in the game when Lionel Messi broke with Luis Suarez in attendance. In a scenario in which it seemed impossible not to score, Messi's pass was not sharp enough, leaving Suarez unable to do anything but hit his shot directly at Leandro Chichizola in the Las Palmas goal.
When Messi scored a free kick soon after, it seemed as though the result might be assured. However, shortly after the halftime interval, referee Antonio Mateu Lahoz spotted an infringement at a corner and Jonathan Calleri scored the resulting penalty.
Barcelona might have felt aggrieved that Chichizola was still on the pitch by the time the game ended, the goalkeeper clearly handling the ball outside the box when challenging Suarez. It was clearly a night to forget in Gran Canaria, then, for the Blaugrana.
Atletico Madrid 4-0 Leganes (La Liga)
On Wednesday, Atletico Madrid put pressure on Barcelona by beating Leganes 4-0 at the Wanda Metropolitana.
Early indications suggested it was likely to be a good night for Antoine Griezmann, the Frenchman hitting the bar from a free kick within the first ten minutes. In the end, he would pick up all four goals for his team, the second making up for his earlier miss with a sumptuous strike from a dead ball situation.
Griezmann's form has been a revelation since the arrival of Diego Costa but this was all about him: his four goals comprising of, amongst other things, a booming header from a Felipe Luis cross and a wonderful volleyed finish at the back post.
With Luis Suarez managing to avoid picking up a yellow card in Gran Canaria, he will be available in this game.
Elsewhere, Jordi Alba will return to his usual place on the left after having been suspended, whilst Nelson Semedo is thought to be out having picked up an ankle injury against Girona last weekend.
With Gerard Pique, Ivan Rakitic and Ousmane Dembele being rested midweek, and Andres Iniesta being played, expect a strong showing for the Atletico game, including a return for Philippe Coutinho.
Atletico Madrid Lineup
Diego Simeone only have Lucas Hernandez and Stefan Savic unavailable to him so expect him to start a team very similar to the one used in midweek, albeit with some rotation.
Key Battle: Lionel Messi (Barcelona) vs Antoine Griezmann (Atletico Madrid)
Whilst this one might be marketed as a battle of the superstars, what is most remarkable about these two teams is that they are both defensively sound this season.
When Sevilla scored two against Atletico last weekend, they became only the second team to score more than one goal against the Madrid-based team in the league this season. Having only conceded two more goals than Simeone's outfit, Ernesto Valverde's team boast a 'goals against' figure of 13 - nine fewer than the next closest team, Getafe.
As a result, this is likely to be a match that closely resembles the dress rehearsal earlier in the season which finished 1-1. With two of the most dangerous strikers in the league battling it out at Camp Nou, the tie could be decided by whichever is the more clinical on the day.
Obviously, Griezmann comes into this one off the back of a four-goal haul against Leganes and so he should be considered the hot favourite to score. However, Lionel Messi, never one to be outdone, is currently running figures of nine goals in ten matches, so don't expect him to be far behind the Frenchman.
Either way, expect this encounter to be an intriguing matchup of two of the best forwards in the world against two of the best defences.
Does Valverde begin tweaking his formation?
It seems unthinkable in 2018 that the La Liga title might be decided by two teams playing 4-4-2 and yet here we are.
Diego Simeone's Cholismo football has long made use of the formation but, for Barcelona, this is a fairly recent innovation brought in by Ernesto Valverde to ameliorate defensive frailties in the team he inherited.
Of late, though, ignoring the Girona performance, Barcelona have struggled to score with anything like prolificacy. With Ousmane Dembele back from injury and Philippe Coutinho settled in, maybe it's time for Valverde to experiment with a new formation?
What affect will their European calendar have on Atletico?
Dropping out of the Champions League has negative aspects that go beyond the embarrassment of leaving the top table of European competition. Atletico now find themselves taking up an extra two fixture as a result of the fact that the Europa League incorporates an extra leg compared to its more famous big brother.
Next week, therefore, Atletico have an away fixture to Moscow to look forward to as they take on Locomotive Moscow in the Round of 16.
Not only does this represent a future annoyance, having played twice in midweek in the weeks preceding this week's La Liga midweek fixture, Simeone's side could well be feeling the physical effects of their clogged schedule. Could this affect them on Sunday?
Prediction: Barcelona 1-1 Atletico Madrid
Much like the earlier iteration of this fixture, expect this to be a tetchy affair where both teams cancel one another out. Where goals come, though, they are likely to come from outstanding pieces of play. With the sort of talent on the pitch, this could be the match of the season, not simply the match which decides the season.