Casemiro will be assessed after a clash of heads with Harrison Reed in the early stages of the second half during Manchester United's 2-1 defeat to Fulham.
The Brazil international received extensive treatment on the pitch before being escorted down the tunnel by head of sports medicine Gary O'Driscoll, clearly in some discomfort after the collision.
It was another blow for the Reds, who were without Luke Shaw and Rasmus Hojlund, after they joined the list of absentees this week.
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