Diego Costa reportedly faces three months on the sidelines at Atletico Madrid due a neck injury that could require surgery.
The Spaniard has played an important part in Atletico's 2019-20 campaign, featuring in 10 of the club's 12 La Liga games since August.
Having featured from the bench during Atletico's most recent game, Costa is said to have been feeling pain in his neck and upper back area.
In a statement released on Thursday, the club's medical team said: "The medical services of the club have conducted radiological tests of Diego Costa to assess the cervical discomfort suffered in recent days.
"These tests have determined that the forward suffers a cervical disc herniation. In the next few days, he will be evaluated by specialists in neurosurgery to establish the definitive treatment."
Costa will be examined by neurosurgery specialists in the coming days ahead of a decision being made over what treatment the condition requires.
Should he go under the knife, the 31-year-old will miss around three months of action.