Atletico Madrid midfielder Koke is reportedly out for three to four weeks with a muscle injury which he picked up in his side's 4-0 thrashing of Real Madrid.
The 23-year-old came off after just 10 minutes of action at the Vicente Calderon, with initial fears that it was a hamstring problem.
Atletico confirmed the injury and duration of recovery through a statement, according to as.com.
Koke's replacement, Saul Niguez, scored the home side's second goal just minutes after coming on.
Koke will likely miss Atletico's next three league fixtures, which include a home game against Almeria and away fixtures against Sevilla and Celta de Vigo.
