Atleti revealed Belgium international Carrasco has sustained an injury setback but did not specify how long he will be out of action.
A club statement read: "Yannick Carrasco has suffered a post-traumatic injury of the left leg musculature, an MRI scan and a medical ultrasound performed at the Clinica Universidad de Navarra confirmed the injury. The Belgian is pending response to treatment."
LaLiga leader Atleti faces Levante at Wanda Metropolitano on Sunday (AEDT), before taking on Chelsea at the neutral venue of Arena Nationala in Bucharest three days later.
Carrasco only recently returned after missing three matches because of a positive coronavirus test.
There was better news on midfielder Thomas Lemar, who is back in contention after recovering from COVID-19, while Moussa Dembele is also nearing a return.
Diego Simeone said: "Yannick has a knock from the game against Granada. It's still affecting him. We'll see how it evolves.
"The good news is Lemar is with us and we look forward to Dembele possibly being able to return tomorrow and to continue adding people as quickly as possible."
Simeone's side is six points clear of second-placed Real Madrid with a game in hand after it was held to a 1-1 draw with Levante on Thursday (AEDT).