Full Match - Aston Villa 6-1 BrightonSep 30
The Portuguese superstar, having fallen out of favour with Erik ten Hag and given an explosive TV interview criticising some of the players, left Old Trafford for a second time in late November by mutual consent.
It was a significant victory for Ten Hag who established his authority over the five-time Ballon d'Or winner and won a debate that had divided the Red Devils fanbase.
And now the pressure is on the Dutch coach to prove he made the right call and he can get the best out of the crop of attacking talent at his disposal and ensure Man United qualify for the Champions League.
The early signs are promising. With Ronaldo not involved, and either side of the World Cup break, Man United have won two and drawn one of their Premier League matches thus far.
But it's a small sample size and Ten Hag will know he'll be scrutinised for every decision he makes especially in selecting his forwards.
Marcus Rashford, after an impressive showing for England in Qatar, has returned to Manchester fresh and raring to go. The Carrington youth product scored in both the Carabao Cup win over Burnley and the Premier League victory over Nottingham Forest and looks ready to be Man United's man man.
In the Forest win, Ten Hag opted for a 4-2-3-1 with Antony, Bruno Fernandes and Rashford behind Anthony Martial leading the line.
Seeing Martial up front has been a sporadic sight for Man United fans who've become accustomed to the Frenchman's unreliability in terms of fitness and form in a red shirt.
Yet Martial did find the net meaning that in nine appearances in all competitions this season, the 27-year-old has scored five times.
Brazil international Antony is a precocious talent who arrived for a huge £86million fee having played under Ten Hag at Ajax. The 22-year-old has shown glimpses of brilliance since joining but his former coach will be tasked with converting potential into consistency from his young winger.
And behind them Bruno Fernandes, a revelation when he first joined the club, had stagnated slightly as the goals and assists dried up significantly last season.
Still, the Portugal star still possesses the decisive pass and vision to unlock any defence and with a stable midfield of Casemiro and Christian Eriksen behind him, Ten Hag will hope Fernandes can rediscover his killer touch.
With youngsters Anthony Elanga, Alejandro Garnacho and Amad Diallo waiting in the wings too, there's plenty of reasons to be excited about Man United's attack in the years to come.
The 4-2-3-1 is a formula that Ten Hag has stumbled upon but is starting to show it's effectiveness. Three defeats in seven Premier League games to start the season has been followed by one and two draws in eight.
There are certainly signs of improvement and with the return of centre back Lisandro Martinez on the horizon following his World Cup exploits, Ten Hag's men will be further bolstered as his side sit just outside the top four.
Ten Hag confirmed the club are considering adding a new striker in January, saying: "We're looking for the right player for our squad and that has to match sporting criteria, but also financial criteria".
Next up is a visit to relegation-threatened Wolves on New Year's Eve to round off 2022 as Man United bid to make it three wins from three in all competitions.
Wolves, under the stewardship of new boss Julen Lopetegui, lifted themselves off the foot of the table on Boxing Day with a huge victory away at Everton courtesy of Rayan Ait-Nouri's late winner.
Yet the west Midlands outfit remain the lowest scorers in the division with just 10 netted in 16 Premier League matches and Man United, who've won their previous two visits to Molineux, will be confident of securing a result.
What follows after Wolves is a run of league matches that could well define Ten Hag's first season in charge. Bournemouth are up on January 3, before a Manchester derby - shown exclusively live on BT Sport, a visit to Arsenal and a home tie with Crystal Palace.
Ten Hag knows it's a period which could define Man United's chances of returning to Europe's top table next season having dropped into the Europa League for 2022/23.