British media said United had closed on a deal worth up to 70 million euros for Casemiro, who has 63 caps for Brazil.
Sevilla topped the Primera Liga on Saturday with a 3-0 home win over Valencia, who had midfielder David Silva sent off after just 17 minutes.
Atletico Madrid maintained a two-point lead in La Liga with a 3-0 victory at Las Palmas and Barcelona and Real Madrid stayed hard on their heels with thumping wins over Athletic Bilbao and Sporting Gijon on Sunday.
Barcelona's Lionel Messi was at the heart of another devastating attacking show.
Valencia continued their solid start to La Liga and climbed to second when recent Spain recruit Paco Alcacer set them on their way to a 3-0 win at Getafe on Monday.
News of all that's transpired on and off the football field
Cristiano Ronaldo ensured Atletico Madrid fans will have bitter memories of the last local derby at the Vicente Calderon stadium by scoring a hat-trick in a 3-0 win for La Liga leaders Real Madrid on Saturday. Ronaldo's deflected free kick put Real in charge in the 23rd minute in the first meeting of the teams since the Champions League final in May. The prolific Portuguese killed off Atletico's resistance by winning and converting a penalty in the 71st minute and capped a harrowing night for the home side by tapping in the third in the 77th.
Sevilla missed a chance to get their La Liga campaign up and running when the Europa League holders surrendered the lead and were held to a 1-1 draw at Levante on Friday.
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.
Real Madrid forward Cristiano Ronaldo faces a race against time to be fit for the Champions League semi-final second leg with Manchester City on May 4.
Cristiano Ronaldo struck midway through the first half as leaders Real Madrid won 1-0 at Malaga in La Liga on Saturday, while Atletico Madrid stayed hot on their heels after Diego Costa netted in a 1-0 victory over Espanyol.
Barcelona have been boosted by the successful return from injury of talismanic playmaker Andres Iniesta as they prepare to host city rivals Espanyol in La Liga on Sunday.
A late goal by Toni Kroos sealed victory as Real Madrid defeated an impressive Celta Vigo side 2-1 to win their first home La Liga game of the campaign on Saturday.
La Liga leaders Real Madrid returned to winning ways after two defeats, making light of playing most of the second half with 10 men to triumph 3-0 at home to mid-table Espanyol on Saturday.
Rodrygo and new recruit Jude Bellingham scored first-half goals to give Real Madrid a 2-0 win at Athletic Bilbao to kick off their LaLiga season.
'We will see, we want to win but at the same time, there are a lot of questions that we need answers to. But in the Asia Cup, I want to see some of the guys batting under pressure against quality teams.'
'Messi is a player that makes a difference in all games and in Clasicos he has always made a big impact but we will have to see if he is ready' 'You never know what can happen in these types of games and when you start as favourite it can often go wrong'
Barcelona fell to a first home defeat in any competition for more than two years
Jose Mourinho believes winning La Liga was the toughest of the seven league titles he has sealed in coaching stints in his native Portugal, England, Italy and Spain, the Real Madrid manager said on Wednesday.
Real Madrid made the most of Barcelona's slip-up to close to within one point of the La Liga leaders on Sunday with a 2-0 win over third-placed Valencia at the Bernabeu.
Title rivals Barcelona and Atletico Madrid stayed locked together at the top of La Liga after they played out an intense 0-0 draw with few genuine chances at the Calderon on Saturday.
Barcelona equalled a club record of 12 consecutive league wins as Neymar and Lionel Messi were among the scorers in a 6-0 thrashing of struggling Getafe 6-0 at the Nou Camp on Saturday.
Barca are now second on 66 points, two behind Real who have a game in hand as they chase a first title triumph since 2012.
Barcelona coach Luis Enrique is expecting another gruelling game at Athletic Bilbao when the La Liga champions visit San Mames on Sunday.
Thierry Henry was on target as Barcelona cruised to a 4-0 home win over Racing Santander on Saturday to move five points clear at the top of La Liga.
Athletic Bilbao checked promoted Villarreal's impressive early-season run when they beat the team with the distinctive canary-yellow strip 2-0 at their new San Mames stadium in La Liga on Monday.
Levante continued to defy their humble status as Valencia's second club when they beat Real Betis 3-1 to reclaim fourth place in La Liga on Monday.
The toughness and guile that made Diego Simeone a great player has been there for all to see in his time as manager of Atletico Madrid, and the Argentinian marks his 300th game at the club with a major challenge on Sunday against Barcelona.
A quickfire Arda Turan double, including an acrobatic bicycle kick, fired Atletico Madrid to a 3-1 home win over Espanyol in La Liga on Sunday and lifted the Europa League semi-finalists up to seventh.
Atletico Madrid suffered a first defeat in 13 games in all competitions as they lost 1-0 at home to Villarreal on Tuesday after a late strike from substitute Roberto Soriano.
Cristiano Ronaldo scored twice as Real Madrid beat Athletic Bilbao 4-2 in a thrilling match at the Bernabeu to move within a point of leaders Barcelona in La Liga on Saturday.
Lionel Messi broke a Spanish hat-trick record and Luis Suarez struck twice as a rampant Barcelona took over top spot in La Liga with a 6-1 hammering of Rayo Vallecano on Sunday.
Luis Suarez played a part in all three of Barcelona's goals in a scrappy 3-1 victory at Granada.
Barcelona still have very little chance of catching leaders Real Madrid and securing a fourth successive La Liga title despite closing the gap to eight points, coach Pep Guardiola said on Monday.
Sevilla became surprise Liga leaders on Sunday after beating visiting Celta Viga 2-1 while champions Barcelona drew 1-1 at Valencia thanks to another Lionel Messi strike but are still without a victory in their last four league games.
Barcelona moved to within a whisker of a second straight La Liga crown when Lionel Messi, Bojan Krkic and Pedro earned a nervy 3-2 win at 10-man Sevilla on Saturday.
Barcelona leapfrogged Atletico Madrid to go top of La Liga after Lionel Messi's acrobatic volley secured a hard-fought 2-1 victory against tenacious Malaga on Saturday.
When asked about Barcelona's youth and talent in midfield especially, Gundogan said he had a lot to offer the team with his experience.
Lionel Messi hit four goals for leaders Barcelona and Cristiano Ronaldo grabbed a hat-trick for Real Madrid as the two teams warmed up for their midweek King's Cup semi-final clash with crushing La Liga victories on Sunday.
An unconvincing Real Madrid needed a controversial Cristiano Ronaldo penalty deep into stoppage time to snatch a 2-1 win at promoted Elche on Wednesday that kept them hard on the heels of La Liga leaders Barcelona and Atletico Madrid.