Last season's treble winners Barca are in their worst run of form in La Liga since coach Luis Enrique took charge in August 2014.
Atletico Madrid striker Fernando Torres is poised to complete a record-breaking move to Liverpool.
Madrid won only two of their seven pre-season games
The three Premier League and three La Liga clubs in the last eight avoided each other, with Manchester City up against Atletico Madrid and Liverpool to face Portuguese side Benfica.
David De Gea has left Manchester United following the end of his contract after 12 seasons with the Old Trafford side.
Bruges scored four times in the last 17 minutes to beat Maribor 4-3 in the Europa League on Wednesday while Atletico Madrid and PAOK Salonika were among six teams to qualify for the knockout stage.
La Liga leaders Barcelona beat Real Madrid 1-0 to all but knock their rivals out of the title race on Saturday, while second-placed Atletico Madrid stayed seven points behind the Catalans with a 2-0 win at Real Sociedad on Sunday.
The Real Madrid forward apologises after Real Madrid dumped out of King's Cup by Atletico Madrid.
Real Madrid have moved to broaden their options in attack by agreeing to sign Mexico striker Javier Hernandez on loan from Manchester United for the 2014-15 season.
News of all that's transpired on and off the football field.
News of all that's transpired on and off the football field
Real Madrid coach Zinedine Zidane shrugged off his first setback since taking over from the sacked Rafa Benitez after his new team could only manage a 1-1 draw at Real Betis in La Liga.
Real Madrid's attacking trio of Cristiano Ronaldo, Gareth Bale and Karim Benzema need to score twice in the Champions League final on May 28 against Atletico Madrid to hit the century mark for goals this season for the first time.
With the Catalans shorn of three of their top forwards, all eyes will be on Griezmann in his first appearance at the Camp Nou since his 120-million-euro ($133 million) move from Atletico Madrid, and not least because Barca need a win to kickstart their season.
IMAGES from football matches played in the Spain, Germany and Portugal on Wednesday.
Cristiano Ronaldo netted his 27th career hat-trick and Gareth Bale struck twice as Real Madrid bounced back in style from consecutive defeats with a thumping 8-2 La Liga win at Deportivo La Coruna on Saturday.
Zinedine Zidane's Real side demonstrated their new-found grit to re-take the lead
Real Madrid need both Gareth Bale and Karim Benzema to step up a level to cover for Cristiano Ronaldo's absence and Marco Asensio will also be given a more prominent role.
There were a few nerves at the end but Liverpool set up a Champions League semi-final with Spain's Villarreal after Roberto Firmino scored twice in a 3-3 second-leg draw with Benfica on Wednesday to ensure a 6-4 aggregate win.
Striker Mariano's header was glanced onto the crossbar by Sociedad's Andoni Gorosabel while the loose ball fell to Marco Asensio, whose shot was deflected wide for a corner from which Raphael Varane header hit the top of the bar.
Manchester City boosted their defensive options by signing Argentine centre back Martin Demichelis from Atletico Madrid on Sunday.
The Indian Super League (ISL) said on Friday it is looking into allegation that former France midfielder Robert Pires was punched in the face by an opposition coach during a halftime altercation in Thursday's match in Goa.
Promoted Alaves dealt champions Barcelona a shock 2-1 defeat at the Nou Camp on Saturday while Cristiano Ronaldo returned from injury to help Real Madrid thrash Osasuna 5-2 and go two points clear at the top of La Liga. With Lionel Messi, Luis Suarez and Andres Iniesta on the bench, Barcelona went behind to the visitors in the 39th minute before Frenchman Jeremy Mathieu equalised in the 46th. Ibai Gomez then scored the winner in the 64th.
Lionel Messi overhauled Real Madrid great Alfredo Di Stefano's La Liga goals tally as Barcelona and Atletico Madrid each won on Saturday to pull three points clear of Real at the top.
Lionel Messi scored twice as La Liga champions Barcelona saw off a persistent Valencia side, who had Eliaquim Mangala sent off in the first half, to win 4-2 on Sunday and stay on the heels of leaders Real Madrid.
Liverpool received a relatively kind draw for the group stage of this year's Champions League
Spain and Liverpool legend Luis Garcia believes that Indian football can touch global heights if the players are given exposure to different leagues abroad and nourish young talents and coaches methodically.
Real Madrid suffered a shock 1-0 home defeat to Real Betis on Wednesday as an inspired performance from their former goalkeeper Antonio Adan and a stoppage-time winner from Antonio Sanabria stunned the Liga champions.
The Polish striker will miss games against Espanyol, Atletico Madrid and Getafe when LaLiga resumes after the World Cup.
IMAGES from the soccer matches played across European leagues over the weekend.
Real Madrid beat Leganes 2-1 in La Liga on Saturday after coach Zinedine Zidane heavily rotated his side in preparation for Tuesday's Champions League semi-final second leg against Bayern Munich, including leaving out top-scorer Cristiano Ronaldo.
Real were smarting from a surprise 1-1 draw at struggling Elche in their last match and were missing captain Sergio Ramos, who was out with a stomach bug.
A second half double from Karim Benzema helped Real Madrid to a 4-1 victory at Girona on Sunday and maintain their perfect La Liga start in the post-Cristiano Ronaldo era.
Real Madrid extended their unbeaten run to 25 matches and rejoined Barcelona and Atletico Madrid at the top of La Liga when Jese, Karim Benzema and Luka Modric scored in a 3-0 win at Getafe on Sunday.
Real Madrid coach Carlo Ancelotti hailed his "extraordinary" players after they set a Spanish record for consecutive victories of 19 thanks to a 4-0 success at home to Ludogorets.
Here, Reuters Sport highlights five reasons why last season's double winners have collapsed.
Manchester United were mistakenly drawn with Villarreal, even though both teams faced each other in the group stage while the Premier League side's ball was not added to the bowl as a potential opponent for Atletico Madrid.
Real Madrid's stuttering season continued as they were reduced to 10 men and then slumped to an 11th La Liga defeat of the campaign by going down 3-1 at Real Sociedad.
'This was why Juventus brought me here. To help do things that they have never done before'
Atletico Madrid coach Diego Simeone praised his team's spirit after knocking holders Barcelona out of the Champions League.