Atletico Madrid defender Diego Godin suffered a sprained ankle ligament in its 1-0 Champions League win over Bayern Munich.
Uruguay centre-back Godin finished the game at the Vicente Calderon on Wednesday with some discomfort in his left ankle.
And an Atletico statement read: "Following a first examination from the medical services of the club, Diego Godin suffered a sprain of the lateral ligament of his left ankle.
"Additional tests will be performed in the next hours."
Godin has played every game this season for an Atletico side that sits third in LaLiga.