Atletico Madrid striker Alvaro Morata (31) sustained a bone contusion and sprained the internal lateral ligament of his right knee during the 1-0 defeat by Sevilla, the LaLiga club said on Monday.
The joint-top scorer in the Champions League this season with five goals from six matches, Morata had limped off the pitch in tears during the 46th minute on Saturday.
Atletico, who next host Las Palmas in the league on Saturday before visiting Italian side Inter Milan for the first leg of the Champions League last 16 next week, did not reveal a timeline for Morata's return.
"On Monday morning he underwent an MRI scan to determine the extent of the injury... He is awaiting further treatment," Atletico said in a statement.
The Spain captain is also Atletico's leading goalscorer in LaLiga this season, having netted 13 times in 22 matches.
