Christian Eriksen made his Red Devils debut in a false-nine role that failed to spark the side into life against Brighton, as Erik ten Hag lost his first game in charge.
Were Ronaldo to start today, then Eriksen would likely drop back into midfield against his former employers to force one of Fred or Scott McTominay out of the starting XI.
Tyrell Malacia, Donny van de Beek and Anthony Elanga are all hoping to step up from the bench and enter the lineup.
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Ten Hag has revealed that both centre-back Victor Lindelof and forward Anthony Martial are injury doubts for the game. Facundo Pellistri, Brandon Williams and Phil Jones are also likely to miss out, meanwhile.
Predicted Manchester United XI (4-2-3-1): De Gea; Dalot, Maguire, Martinez, Shaw; McTominay, Eriksen; Sancho, Fernandes, Rashford; Ronaldo.