The Red Devils severed ties with the 54-year-old less than 24 hours after Sunday's agonising 2-1 loss to West Ham United, a result that left the 20-time English champions 14th in the top-flight table amid their worst-ever start to a Premier League campaign.
Ten Hag was given the boot just a few months on from being given a new contract by Sir Jim Ratcliffe's INEOS regime, who offered him a stay of execution following their FA Cup success last season but could not ignore pitiful performances for much longer.
Ten Hag's former assistant Ruud van Nistelrooy has temporarily assumed the role of first-team manager as Man United search for a permanent replacement, but they will no doubt find hiring a successor much more challenging now than if they had bitten the bullet over the summer.
Thomas Tuchel and Mauricio Pochettino have both entered the world of international management with England and the USA respectively, Zinedine Zidane is still waiting for the France gig, and prising any of Thomas Frank, Kieran McKenna and Ruben Amorim away from their current clubs midway through the season will surely prove far too difficult.
Gareth Southgate is in no rush to come back to the chair either, but a handful of top coaches are waiting for their next big-money contracts, so with that in mind, Sports Mole looks at four realistic Ten Hag successors Man United could target in the coming weeks.
Xavi
Believed to be near the top of Man United's refreshed shortlist of Ten Hag replacements, ex-Barcelona boss Xavi has been out of work since leaving the La Liga leaders at the end of a 2023-24 soap opera.
After affirming for months that he would not go back on his public decision to leave the club at the end of the campaign, Xavi performed an incredible U-turn and decided to stay after all, only to seemingly rub president Joan Laporta up the wrong way with his comments about Barca's financial situation.
At the end of it all, Xavi left his position as head coach and is thought to have been contacted by Red Devils CEO Omar Berrada over the Man United gig, and having already conquered one top European division in the shape of La Liga, the 44-year-old would be a highly intriguing prospect.
Edin Terzic
A man who worked his way up from a club scout to a Champions League finalist, ex-Borussia Dortmund boss Edin Terzic masterminded BVB's run to Wembley last year, where they gave Real Madrid a brilliant run for their money for the most part.
Missed chances memorably came back to bite Dortmund in that 2-0 loss to the 15-time European champions, after which Terzic unexpectedly handed in his resignation to the Dortmund offices following scathing criticism of his style of play.
The Athletic reports that Terzic struggled to get his BVB squad to gel as one without the generational Erling Haaland or Jude Bellingham, so while the 41-year-old is immediately available and supposedly ready to take on a new job, he may not be the best bet for a Man United side crying out for cohesion.
Graham Potter
Flash back to the end of September, when Graham Potter was grilled on Sky Sports News' Monday Night Football segment about his prospective return to football with either England or Man United after a year and a half out of the game.
The former Chelsea boss confirmed that "conversations" had taken place behind the scenes without specifying which outfits he had spoken to, and he will almost certainly be on Ratcliffe's radar given that the INEOS chief is said to be targeting the 'best of British' for his Man United project.
However, Potter at Chelsea always had the feeling of a small fish in a big pond, and there is no suggestion that it would be any different at Man United, although it would be interesting to see if he could help resurrect Mason Mount's career following their time together at Stamford Bridge.
Massimiliano Allegri
Perhaps the least popular name on this four-man shortlist, the ever-fiery Massimiliano Allegri is on the lookout for a new venture after leaving Juventus for the second time in disgrace at the end of last season.
Even though his Bianconeri side beat Atalanta BC in the Coppa Italia final, Allegri went into meltdown mode, allegedly threatening a reporter and also giving the officials an earful before the Old Lady board gave him the inevitable boot.
Italian media reported last month that Man United had made contact with the pragmatic 57-year-old, who knows more than a thing or two about winning silverware, but his emphasis on defence and volatile nature makes it difficult to envisage a scenario in which Allegri at Man United does not end in disaster.