Trent Alexander-Arnold was forced off the pitch with an apparent hamstring injury just minutes into his Champions League debut for Real Madrid.
The 26-year-old has had a difficult start to life with Los Blancos, and has been battling with Dani Carvajal for a place in Xabi Alonso's starting line-up.
But after getting the nod from the Spaniard for Tuesday night's fixture against Marseille, Alexander-Arnold made it through just three minutes until he went down clutching his hamstring.
Alexander-Arnold cut a frustrated figure on the grass as he was treated by medical staff and his teammates surrounded him.