The loss of Mbappe adds to the mounting pressure on manager Alvaro Arbeloa, whose side now sits eight points adrift of La Liga leaders Barcelona. Medical reports from sources at ESPNhave reinforced the suspicion of a muscular issue, suggesting a period of recovery may be necessary.
Addressing the media after the final whistle regarding the forward's condition and the discomfort that prompted the change, Arbeloa said: "I have no idea [what's wrong with Mbappe]. He felt some discomfort. We'll see how he evolves over the next few days."