Louis van Gaal started a new era at on Wednesday as the Dutch manager arrived for his first day in charge of the fallen giants.
Just days after securing the Netherlands' third place finish at the World Cup, van Gaal jetted into Manchester to begin the task of restoring United to their position as the Premier League's preeminent force.
The 62-year-old Dutchman was appointed as replacement for the sacked David Moyes two months ago, but his World Cup commitments meant he had to wait until now to officially take the reins at Old Trafford.
Van Gaal faces a significant rebuilding job after United endured a miserable campaign under Alex Ferguson's hand-picked successor Moyes, finishing seventh in the Premier League and failing to qualify for the Champions League.
With much to do, van Gaal, back in club management for the first time since leaving Bayern Munich in 2011, was so keen to get down to business that he opted against taking a holiday after the World Cup.
The former Barcelona boss arrived in England on a private plane and was whisked from the airport to United's Carrington training ground in a Chevrolet car.
Van Gaal was welcomed by his new assistant, United legend Ryan Giggs, and the club's chief executive Ed Woodward, who gave the Dutchman a tour of the training ground after posing for pictures posted on the team's official Twitter feed.
Dressed smartly in a blue suit, van Gaal may have raised a few eyebrows in Manchester for choosing a blue and white tie - the colours of arch rivals and Premier League champions Manchester City - rather than the red of United.
Van Gaal had already sent an advance party to Manchester ahead of his arrival and his assistant coaches Albert Stuivenberg and Marcel Bout took the first training session of the day along with Giggs before their manager's arrival.
After revealing earlier in the week that he hopes to emulate the strong team-spirit which helped the Netherlands mount a strong challenge at the World, van Gaal was due to meet his new players for the first time before putting them through their paces in the second training session of the day at 5.30pm local time.
The two-a-day sessions are designed to boost the players' fitness after the close-season and United's Brazilian defender Rafael da Silva was keen to embrace the challenge, tweeting a picture from inside the dressing room captioned 'Let's go, two sessions'.
Van Gaal, who won the Champions League with Ajax in 1995 and a combined seven domestic league titles in Spain, Germany and Holland, will be officially presented at a press conference at 3pm local time on Thursday before flying out to the United States on Friday for the club's pre-season tour.
United will play matches against the Los Angeles Galaxy, Roma, Inter Milan and Real Madrid before beginning their Premier League campaign at home to Swansea on August 16.
Those matches will give van Gaal his first chance to see new signings Luke Shaw and Ander Herrera in action.
England left-back Shaw, 19, arrived from Southampton for £30 million, making him the most expensive teenager in the history of the game, while Spanish midfielder Herrera cost £29 million from Athletic Bilbao.
That £59 million spree isn't likely to be the end of van Gaal's spending, with the manager reportedly keen to sign an experienced centre-back following the departures of Nemanja Vidic and Rio Ferdinand, while also looking to add more pace and creativity on the wings.
Given United just announced a record £750 million (€942 million, $1.28 billion) kit deal with Adidas, there is little doubt he can afford to continue splashing the cash.
Also on van Gaal's to-do list is appointing a new captain to replace Vidic.
United striker Robin van Persie filled that role with the Netherlands, making him the favourite to take the armband.
But van Gaal must guard against annoying Wayne Rooney, who is keen on being captain himself and is said to have a prickly relationship with van Persie.