Beating Antony to the top of this list is no easy feat, but Andre Onana is a truly special case. The calamitous Cameroon goalkeeper is not just the worst signing of the Glazer era, he's the worst in United's entire history, and perhaps even the Premier League's.
Onana was initially billed as an upgrade on David de Gea after he arrived from Inter in the summer of 2023 for a £48m fee, having played a key role in the Italian club's run to the Champions League final. He was supposed to be United's answer to Alisson and Ederson, a ball-playing 'keeper who could elevate the team to genuine title contenders, and the expectation was he would hit the ground running after being reunited with his former boss at Ajax, Ten Hag.
But right from day one, quite literally, something seemed wrong. Onana's distribution in United colours was never even close to the level it was at Inter; in fact, fans automatically held their breath whenever the ball was played back to him, because 99 percent of the time, he would either smash it out of play or give the ball straight to the opposition.
He was also incapable of commanding his box, and anytime he did come off his line, it sparked automatic panic in the defence. Positionally, Onana was all over the place while his communication skills were sorely lacking. Those are all weaknesses that could be forgiven, or at least papered over, if Onana's shot-stopping was up to scratch, but that was the biggest hole in his game of all.
Onana made so many basic handling errors that it would take far too long to list them all here. He was, though, single-handedly responsible for some of United's most embarrassing defeats over the past two years, including the 2025 reversal at League Two Grimsby Town in the Carabao Cup, because he seemingly did not know how to get his body behind the ball or have the reactions to deal with simple shots that should be meat and drink for any professional goalkeeper.
It's quite astounding that he has been allowed to stay at Old Trafford this long, given his gross incompetence. There was a new entry in Onana's reel of shame every time he took to the pitch, a monumental failure who doesn't deserve another chance at the top level when he is finally kicked to the curb following his return from a loan spell at Trabzonspor.