Real Madrid defender Raphael Varane suffered a thigh muscle tear in Wednesday's 2-1 defeat to Valencia at the Mestalla Stadium.
The Frenchman hobbled out of the game in the 73rd minute and was replaced by Nacho Fernandez, and it is thought that his amount of football since the turn of the year has contributed to the injury.
Zinedine Zidane could now be out of action for the next few weeks, and will likely miss the games against Villarreal, Las Palmas, Eibar and the second leg of the Champions League last-16 tie with Napoli.
Spanish newspaper Marca report that Real will hope to confirm the centre-back's lay-off time on Friday, as they wait for the inflammation of the area to settle - which has delayed the club's desire to carry out proper tests thus far.
Varane's injury is expected to take at least two weeks to heal, which will come as blow to los Blancos given how he had been playing in the Madrid backline.
It was a hugely disappointing night for Madrid, who could have extended their lead over Barcelonaat the top of La Liga to four points with a game in hand.
They remain a point aheadof their bitter rivals but face atricky test against Villarreal, who are currently sixth in the league and boast the best defensive record in the division - they have conceded just 15 goals in 23 top flight matches this season.