Barcelona meet Atletico Madrid on Sunday in what will be a huge title test for both teams in La Liga.
Ernesto Valverde's side saw their lead cut to five points at the top of the table after they were held to a 1-1 draw by Las Palmas in the Canary Islands on Thursday and, after arriving on the mainland just before 4am on Friday morning, their players were back in training at 12:30 to prepare for Sunday's big game.
Atletico, meanwhile, were in action at home to Leganes on Wednesday and won that match 4-0, with all four goals scored by Antoine Griezmann. Diego Simeone's side have only lost once all season and drew 1-1 with Barca at the Wanda Metropolitano back in October.
Here, Goal takes a look at everything you need to know ahead of Sunday's clash at Camp Nou...
Nelson Semedo is expected to be out for five weeks after picking up a hamstring injury in last Saturday's 6-1 win at home to Girona.
Meanwhile, Sergi Samper is out with a long-term problem. The midfielder was on loan at Las Palmas, but damaged ankle ligaments in a game against Eibar in January and has returned to Barcelona for the rest of the season in order to recover and receive treatment.
Jordi Alba picked up his fifth league booking of the season against Girona and missed the trip to Las Palmas, but he will be available again this weekend. Meanwhile, Luis Suarez managed to avoid a yellow card on Thursday and will feature, although he is still just one booking away from a ban.
Barcelona potential starting line-up
Barcelona remain unbeaten in La Liga and coming through this match with that record intact will make the Blaugrana big favourites to claim the title at the end of the season.
Valverde will therefore pick his strongest side and the only real doubt is in midfield, with Andres Iniesta, Philippe Coutinho and Ousmane Dembele competing for two spots alongside Sergio Busquets and Ivan Rakitic.
If Iniesta starts, Coutinho could feature as well, but given that his preferred position is also on the left, Dembele may get the nod to provide more balance on the right.
With Semedo injured, Sergi Roberto will start at right-back, with Alba back from suspension to replace Lucas Digne on the left. Gerard Pique, rested on Thursday, will return alongside Samuel Umtiti in central defence.
Atletico Madrid team news
Atletico have lost just once this season in La Liga and are on form after thrashing Sevilla 5-2 away from home and then Leganes 4-0 in their last two league games.
Griezmann scored seven goals in those two matches and his partnership with Diego Costa in attack is really starting to blossom for the Rojiblancos.
Simeone's side have a small squad for the remainder of the season after Yannick Carrasco and Nico Gaitan both moved to China and goalkeeper Miguel Angel Moya joined Real Sociedad this week.
In addition, defenders Lucas Hernandez and Stefan Savic are doubtful for Sunday's game.
TV channel & kick-off time
Barcelona versus Atletico kicks off at 16:15 local time on Sunday and will be broadcast live in the UK (United Kingdom) on Sky Sports Mix from 15:00 GMT.
In the United States, the game can be watched live on television on beIN SPORTS and kicks off at 10:15 ET.
Best Opta match facts
Barcelona have not lost any of their last 15 games against Atletico in La Liga (11 wins and four draws), their best unbeaten run against them in the competition.
Atletico have just lost just once in their last 24 La Liga games away from home (won 15, drawn eight), a 1-0 defeat against Espanyol in December.
Simeone (eight defeats and four draws) has never beaten Barca as a coach in La Liga.
Atletico are Lionel Messi’s second favourite opponent in all competitions (27 goals scored) after Sevilla (29).
Only against Villarreal (nine) has Fernando Torres scored more goals in La Liga than against Barcelona (eight, same as against Athletic), although his last league goal at Camp Nou in the competition was 12 years ago (a double in February 2006).