Atletico Madrid have confirmed that Diego Costa sustained a hamstring injury in Saturday's 1-1 draw against Girona and will continue to be monitored.
The Spain striker was substituted just after the hour for Kevin Gameiro, with Diego Simeone's decision to then bring off Antoine Griezmann 10 minutes later leading to jeers from the home crowd with the team leading 1-0.
Simeone said after the match that Costa had asked to come off due to injury, and the former Chelsea striker underwent further medical examinations on Sunday.
Atleti confirmed on Twitter that Costa has sustained a hamstring problem, although a time frame on his return was not announced with a further statement on the club's official website adding the situation will be monitored.
Reports in Spain suggest that Costa will miss 10 days, meaning Atleti will be without the striker for Wednesday's second leg of the Copa del Rey tie at Sevilla, which they trail 2-1.
Costa, 29, would also miss Atleti's league game against Las Palmas on home soil next Sunday, should he be out of action for that period of time.
The forward returned to the Colchoneros from Chelsea in January and has scored three goals in all competitions so far for the Spanish outfit.