Atletico Madrid could be without a fit right-back for Tuesday's Champions League semi-final, first leg against Real Madrid after Jose Maria Gimenez suffered a groin injury in Saturday's 5-0 win at Las Palmas.
Gimenez is naturally at centre-back, but has deputised at right-back in recent matches with both Sime Vrsaljko and Juanfran also sidelined by injury.
"Gimenez suffered a muscular injury in his left adductor," Atletico said in a statement. "Our player will undergo further tests in the next few hours."
Atletico have been beaten by Real in the Champions League in the past three seasons, including in the final in 2014 and 2016.
However, Diego Simeone's men will travel to the Santiago Bernabeu in fine form as a Kevin Gameiro double and goals from Saul Niguez, Thomas Partey and Fernando Torres sealed a 5-0 rout in the Canary Islands to move three points clear of Sevilla in third in La Liga.