Gameiro finished Sunday's clash with muscle problems, prompting an MRI scan on Monday, while Costa also had an MRI to evaluate the bruising to his ankle, after it was stomped on by Celta defender Sergi Gomez, reports Efe.
Atletico said Gameiro's scan confirmed he had had "a myofascial injury in the adductor muscle of the right thigh."
Gameiro and Costa missed Tuesday's training session at the Wanda Metropolitano stadium, and Solvenia goalkeeper Jan Oblak was also absent, practicing separately at the gym.
Atletico Madrid is to travel to Moscow on Tuesday for the UEFA Europa League round of 16 match against Lokomotiv Moscow, set for Thursday.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
