LaLiga: Raphael Varane double leads Real Madrid comeback win at Huesca; Sevilla beat Getafe as coaches clash
The victory moved Real Madrid back into second place in the standings, closer to league leader Atlético Madrid.
Ramos is expected to be out for six to eight weeks, meaning he would miss both Champions League games, dealing a huge blow to Madrid.
European football matchday: Manchester United host Everton in Premier League; Real Madrid take on Huesca in LaLiga
Juventus and Roma face each other in Serie A knowing the winner can close in on the top two.
Real Madrid lost at home to Levante last weekend and travel to last-place Huesca on Saturday third in the table and 10 points behind leaders Atletico Madrid.
When the transfer window closed on Monday, Real Madrid didn't sign for a second straight window while Barcelona's Ronald Koeman was told the club could not find even three million euros for a central defender
European football weekend: Manchester City at Anfield, Le Classique in Ligue 1 and Mesut Ozil in Istanbul derby
What to look forward to in European football this weekend from Premier League, LaLiga, Bundesliga, Serie A and Turkey.
LaLiga: Real Madrid attacker Eden Hazard damages left thigh muscle, expected to be sidelined for a month
Hazard is expected to be out for around a month, meaning he would miss Madrid's first leg away at Atalanta in the Champions League on 24 February.
Perez's positive test comes after Real Madrid coach Zinedine Zidane also tested positive last month.
Another transfer window in Spain passed quietly on Monday as none of the top teams made big signings while they continue to feel financially smashed by the coronavirus pandemic.
LaLiga: Luis Suarez brace takes Atletico Madrid 10 points clear; Barcelona level with Real Madrid in second
Antoine Griezmann also scored for Barcelona, who won their fifth in a row in the league and moved into second place for the first time this season.
LaLiga chief Javier Tebas accuses FIFA president Gianni Infantino of supporting European Super League
Documents containing details of the Super League, first reported this month by British newspaper The Times, proposed a 20-club tournament with 15 permanent members.
Militao was shown a red card in the ninth minute at the Alfredo di Stefano Stadium, with his team already without their injured captain Sergio Ramos and COVID-stricken coach Zidane.
Premier League: Jose Mourinho says Tottenham Hotspur won't use Gareth Bale as striker in Harry Kane's absence
Harry Kane suffered injuries to both ankles in the first half of Tottenham's 3-1 defeat against Liverpool on Thursday and did not appear after half-time.
Copa del Rey: Lionel Messi scores on return from suspension to guide Barcelona to win over Rayo Vallecano
Messi tapped in Antoine Griezmann's pass to equalise before turning creator, sending Jordi Alba through, with Frenkie de Jong at the back post to seal a 2-1 victory.
Premier League: Arsenal sign Norwegian midfielder Martin Odegaard from Real Madrid on loan till end of season
Odegaard shone when on loan at Real Sociedad last season, but has struggled for game time since returning to the Spanish champions this campaign.
The last time Özil featured in a matchday squad for Arsenal was on 25 June against Southampton. It's doubtful whether he's even been to the Emirates Stadium very much since then
The home victory against Getafe left Athletic in ninth place in the Spanish league, closer to the qualification spots for European competitions.
European football matchday: Real Madrid to play Alavés without Zinedine Zidane; Manchester City vs Cheltenham in FA Cup,
A look at what’s happening in European football on Saturday
The positive test comes a day before Madrid travel to Alaves in LaLiga seeking to bounce back from an embarrassing midweek Copa del Rey exit.
Humiliated in the cup by Segunda B's Alcoyano, a week after being outfought and largely outplayed in the Spanish Super Cup by Athletic Bilbao, Madrid find themselves in another slump.