Diego Costa could miss Atletico Madrid's La Liga clash with Getafe on Saturday afternoon.
Costa, 29, re-joined Atletico from Chelsea in the latter stages of 2017, but had to wait until the start of January to make his long-awaited return to the field.
The striker netted five minutes after coming off the bench against Lleida in the Copa del Rey on Wednesday night, and had been expected to lead the line against Getafe this weekend.
Atletico, however, have confirmed that Costa picked up 'a knock' during the cup match, which makes him a doubt for the La Liga fixture at the Wanda Metropolitano.
"Diego Costa has recovered well from the knock taken to his leg which caused him problems in his knee," read a statement from Atletico.
"Today our forward worked in the gym with the rest of his teammates, taking part in a recovery session and afterwards undergoing some scans. His availability depends on how the recovery goes."
Costa is currently in his third separate spell with Atletico.