Ronaldo may have injured his knee doing his trademark 'siu' celebration after scoring from the penalty spot in victory over Arsenal in midweek.
The Sun says the Portugal international demonstrated no immediate ill-effects, running the length of the pitch in 12 seconds to support a late counter attack in the 87th minute.
However, he was substituted for Anthony Martial with two minutes of the 90 remaining, and was seen walking awkwardly off the pitch.
If he is ruled out, it will come as a big blow to interim boss Ralf Rangnick, who is set to take charge of his first game against Patrick Vieira's Crystal Palace on Sunday afternoon.
Source: Tribalfootball
Any link buliding on our comment section will be make as spam.