Bruno Fernandes did not request to be substituted during Manchester United's defeat at Liverpool.
Former United captain Gary Neville, on co-commentary for broadcasters Sky Sports, claimed Fernandes was requesting to come off for Anthony Elanga when Marcus Rashford was withdrawn.
United sources say Fernandes sought clarification on his position after the 85th-minute change with Liverpool 6-0 up. Liverpool scored a seventh in the 88th minute.