Atletico Madrid will almost certainly be without Juanfran for their La Liga clash against Barcelona on Saturday evening.
The defender was diagnosed with a “myofascial injury to the gastrocnemius muscle” in his calf on Thursday.
Fellow defender Diego Godin could be sidelined with a thigh injury but Diego Costa may return after a foot complaint.
Atletico boss Diego Simeone said: “We have a new opportunity against a great rival.
“We will try to take the game to where we think we can harm them. We will go in search of that.”