Casemiro was another standout performer for United, scoring a deflected goal and providing an assist. He was also exceptional against reigning Premier League champions Liverpool, clearly thriving on a once-a-week playing schedule.
However, Amorim may soon have to plan for a match without Casemiro, and not due to injury. The Brazilian is already on three yellow cards, and two more before United's 20th league game will result in a one-match ban.
Another potential suspension concern arose during United's clash with Brighton. During Danny Welbeck's superb free-kick that brought Brighton back into the game, Patrick Dorgu fouled Yankuba Minteh as he broke through on goal, potentially jeopardising United's upcoming trip to Nottingham Forest.
The Denmark international was only given a yellow card as it was deemed that Minteh's heavy touch meant it was not the denial of a clear and obvious goal-scoring opportunity. However, this is his third booking of the season, putting him in the same predicament as Casemiro.
Amorim has shown a preference for using Diogo Dalot at left wing-back over Dorgu when deploying Amad on the opposite flank, but he too has been cautioned three times.
In terms of potential replacements for Casemiro, both Manuel Ugarte and Kobbie Mainoo can be deployed alongside Bruno Fernandes, although Amorim would undoubtedly prefer to have Casemiro available, considering his recent impact.