Real Madrid did not announce a recovery time for Eden Hazard but his latest setback will be a worry for Belgium boss Roberto Martinez ahead of Euro 2020 this summer.
Real Madrid's nightmare afternoon was made worse by another injury to Eden Hazard, who was forced off in the second half of their 0-1 defeat to Levante.
Eden Hazard's comeback also coincided with Real Madrid conceding twice in a league game for the first time since October, even if they did let in three in the Copa del Rey against Real Sociedad two weeks ago.
Barcelona were beaten 0-1 by Athletic Bilbao at San Mames while Real Madrid lost 3-4 in a seven-goal thriller to Real Sociedad at the Santiago Bernabeu.
Barcelona can cut the gap back to three points by beating Levante at home on Sunday but Atletico Madrid now trail leaders Real Madrid by 13 points.
If Eden Hazard returns against Sevilla in La Liga on January 18 he will have been out for almost eight weeks.
Eden Hazard could be sidelined for more than a month after suffering a fracture in his ankle while Marcelo might also miss the game against Barcelona, after he sustained a calf strain in training.
Eden Hazard had shown glimpses of his best form in recent weeks after a slow start in Spain, in part due to a thigh strain he picked up at the beginning of the season.
Lionel Messi delivered an incredible dead-ball hat-trick on Saturday to steer Barcelona to a 4-1 victory over Celta Vigo.
Euro 2020: Romelu Lukaku took his record international tally past 50 goals as Belgium opened up an unassailable 11-point lead over third-placed Cyprus.
Eden Hazard had become a growing concern after five underwhelming matches, the patience granted to him after his injury in pre-season beginning to run out after his 100 million euros move from Chelsea.
Eden Hazard joined Real Madrid in the summer but is yet to score a goal or register an assist
Real Madrid are a point ahead of promoted Granada and Atletico Madrid after Diego Simeone's side failed to break down their well-drilled local rivals.
Eden Hazard missed the start to Real Madrid's season with a thigh injury, and has failed to impress in the matches he has played so far
Real Madrid vs Osasuna: Eden Hazard and Gareth Bale were among a number of players rested by coach Zinedine Zidane, with Real Madrid facing seven games in 21 days.
Karim Benzema's brace helped Real Madrid secure three points at home against Levante.
Eden Hazard was expected to make his debut in Vigo in the opening round in mid-August after joining Madrid for an initial 100 million euros from Chelsea in June.
Harry Kane scored the only goal of the game with a deft finish after pouncing on a disastrous pass by Marcelo.