From the first round onwards, replays have now been scrapped, a consequence of the expansion of UEFA's European competitions.
Ties must be decided on the day, through extra-time or penalties, if required.
United's last replay came against Wolves in early 2020, winning 1-0 at Old Trafford, thanks to a goal by Juan Mata, following a 0-0 draw at Molineux.
Of course, there have not been replays for the latter stages for some time - our epic 1999 semi-final victory over Arsenal at Villa Park was the last rematch at that stage of the competition.