The beginning of the end for Amorim? Man United's shocking loss to fourth-tier Grimsby raises the possibility

GRIMSBY, England -- Ruben Amorim will never forget his trip to Grimsby. He certainly won't want to go back. A 12-11 penalty shootout defeat Wednesday against a side from EFL League Two after a 2-2 draw in regulation was a new low for Manchester United and their beleaguered coach, and it might just prove to be the night when his grip on his job started to unravel.

Make no mistake, losing to Grimsby Town is a humiliation for Amorim and United. Never before had United lost to a team from England's fourth tier in this competition -- they had won their 11 previous ties against teams from that division -- but it was the manner of the second-round exit that could put Amorim in peril.

United had trailed 2-0, almost going three down before Cameron Gardner's second-half goal was ruled out for offside, but a late rally saw them haul themselves back to 2-2 with goals from Bryan Mbeumo and Harry Maguire. Before a chaotic shootout, marked by misses by strikers Matheus Cunha and Mbeumo, £74 million summer signing Benjamin Sesko shot over from six yards with the last kick of the game. That should have been an omen for what was to come next.

After witnessing his side lose on penalties, Amorim gave a cryptic assessment by saying his players "spoke loud for me." It didn't sound like a compliment.

"When you play against a fourth-division team, it's not the goalkeeper [that costs you the win], it's everything." Amorim said. "It's the environment, it's the way we face the competition. We know that we are in a moment when people will pay attention to everything.

"It's going to be massive, every detail, and we show that performance today. So my players spoke for me really loud."

United's hugely expensive group of players should have had far too much for Grimsby, regardless of its slow start to the Premier League season that has seen it lose and draw their opening two games.

But a combination of the home team's spirit and organization and Amorim's refusal to accept that his favored 3-4-3 system does not suit his players led to United suffering their worst cup defeat in memory.

There were so many side stories in this game -- the poor defending by Diogo Dalot and Tyler Fredricson, goalkeeper André Onana's hopeless attempt at dealing with the corner that led to Grimsby's second goal, the inability of midfielders Kobbie Mainoo and Manuel Ugarte to control the game and dominate the central third of the pitch and the careless penalty taken and missed by Cunha that would have won the shootout for United.

But all of those subplots are part of the grim, bigger picture at United. They are not isolated incidents from a night in Grimsby. Amorim has had goalkeeper problems all season, his team's defending has been poor, United don't have a functioning midfield and penalties have been an issue -- Bruno Fernandes missed at Fulham at the weekend. But with the summer transfer window due to close on Sept. 1, time is running out for United to do much about solving their many problems. They need a reliable goalkeeper, but they probably won't sign one. There is a desperate need for a midfielder who has the energy to run box to box, but also the skill to create and control the game.

Yet for all of those issues, the biggest one has become the elephant in the room -- Amorim's stubborn adherence to his 3-4-3 system. It simply doesn't work in the Premier League, where United are outnumbered in central midfield, but Amorim continues to jeopardize his hopes of retaining his job by refusing to change his approach. The midfield problem also means that the forwards are starved of service -- an issue exacerbated by Amorim's preference of playing with inverted wide players who would rather cut inside than cross for the forwards.

- Arsenal or Chelsea to win PL, Estevao better than Gyokeres? Week 2 overreactions - Sources: Chelsea closing in on £40 million transfer for Man United's Garnacho - Striker domino effect: How Liverpool, Chelsea, Man United and others net out

It is a mess in every department, but because United have been such a shambles for the best part of a decade, chopping and changing managers every two to three years, there is a determination to weather the storm with Amorim until he gets it right. But this is proving to be a long storm, and the clouds are beginning to get even heavier.

Amorim could not escape the chants of "You're getting sacked in the morning!" from gloating Grimsby fans. They are probably wide of the mark for now, but there is no escaping Amorim's poor record. He was afforded time and patience last season because he inherited a dysfunctional squad from Erik ten Hag in November, but this is now his team, and his win ratio is by far the worst of any United manager since Sir Alex Ferguson retired in 2013.

Grimsby was Amorim's 45th game in charge and his 19th defeat. He has overseen more defeats than wins (17) in 10 months as manager. But this is the one that will sting more than any other, and it might also prove to be a line in the sand.

United and Amorim cannot continue like this. Grimsby has to be the lowest of the low, but with this team, there is always a chance of things getting even worse.