Eden Hazard hobbled off during Real Madrid's LaLiga game at Levante on Saturday - giving Zinedine Zidane a major injury concern ahead of a crucial week for the club.
The Belgium international, who has only recently returned from a fractured ankle, was clearly in pain as he was replaced by Vinicius Junior in the 67th minute with the score at 0-0.
Hazard could be seen sitting on the visitors' bench receiving treatment to his lower right leg, with Zidane now waiting to discover the full extent of the problem ahead of two huge home fixtures.
Madrid, who went on to lose 1-0 to Levante, host Manchester City on Wednesday in the first leg of their last-16 Champions League tie, followed by the visit of title rivals Barcelona in league action next Sunday.
Hazard was making just his second outing since requiring surgery on his right ankle after he was hurt against Paris Saint-Germain on November 2.
His debut campaign in the Spanish capital got off to a delayed start following a thigh injury in pre-season, forcing him to wait until September 14 to make his debut following his arrival from Chelsea in June.