Shortly after the beginning of the second half against Southampton, Rasmus Hojlund lost his umpteenth duel of the match and Ruben Amorim finally decided he'd seen enough. Amorim summoned Joshua Zirkzee to prepare to be introduced and Hojlund was hooked off the pitch.

Amorim has form for being reactive on the touchline and isn't afraid to haul an underperforming player off, so what was he thinking when Andre Onana made an error on Sunday?

From a technical standpoint, Onana's mistake against Brighton was horrendous. The early cross into the box from Yasin Ayari lacked power and should have been easily gathered, but Onana fumbled and spilled it to Georginio Rutter, who probably couldn't believe his good fortune.

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Although there were 15 minutes of the game remaining and substituting a goalkeeper is publicly humiliating, you wouldn't have blamed Amorim if the thought had crossed his mind.

Onana survived until the final whistle, but he might not keep his starting role on Thursday night when United welcome Rangers to Old Trafford in the Europa League because Altay Bayindir will feel he deserves the opportunity to start following his teammate's howler against Brighton.

Bayindir started in the FA Cup third round against Arsenal and delivered a heroic performance, making crucial saves in normal time and saving two penalties in the shooutout victory.

It was a pivotal moment for Bayindir and his only meaningful contribution since signing from Fenerbahce. His passing was wayward throughout the match and he unconvinced with his feet, but Bayindir denied Arsenal with some excellent saves and increased the pressure on Onana.

Bayindir and Onana both signed for United in the summer of 2023. The Turkish international has been the understudy and Erik ten Hag hardly ever started him in cup competitions.

Ruben Amorim has taken a different approach and surprised journalists in his pre-Arsenal press conference when he confirmed Bayindir would start, despite conceding from a corner in the Carabao Cup defeat to Tottenham and being culpable for United's exit from that competition.

Amorim showed faith in Bayindir and he vindicated his selection against Arsenal. Onana's status as United's first-choice goalkeeper had never been under threat until that performance and Bayindir's display would have made him feel some insecurity for the first time, which is healthy.

Theoretically, the increased pressure should be conducive to Onana improving his performance levels, although the opposite happened against Brighton when he committed a blunder.

Onana struggled during an error-strewn six months at the club, but he enjoyed a mostly consistent calendar year of 2024 and it seemed like mistakes had been eradicated from his game.

Then it all started to go down hill for Onana when United lost 2-0 against Arsenal in December. The 28-year-old conceded two goals from corners and followed that performance with a huge mistake against Nottingham Forest, and another error against Viktora Plzen in the Europa League.

Onana's confidence has taken a blow and Amorim will be considering starting Bayindir against Rangers, which could see Onana lose his place for tactical reasons for the first time.

It is never straightforward to drop a goalkeeper. It could do more damage than good and Amorim must weigh up how Onana would react, and whether he is set to be his long-term first-choice because the Cameroon international hasn't made a strong impression during their time together.

There has been a suggestion that Onana needs to be replaced and Amorim will give a clue about his future at United, depending on who he selects to start against Rangers on Thursday.

Bayindir isn't the most convincing second option but he is currently the form pick to start.