Chelsea forward Alvaro Morata picked up what appeared to be a hamstring injury in Saturday's Premier League match against Manchester City.
Per the club's official Twitter account, he was unable to continue after slumping to the pitch in the first half. According to ESPN FC's Mark Ogden, he clutched his hamstring as he did so.
Morata joined the Blues in the summer for a club-record transfer fee after just one season back at Real Madrid.
The Spain international left the Santiago Bernabeu for Juventus in 2014 in search of regular football, and after a couple of campaigns in Italy, he returned to Real.