The message from the Portuguese international was simple: "I am ready to go." The 36-year-old reiterated this week that he isn't here for a vacation - he's here to win things.
Following years of stagnation, this is a message that United fans have been desperate to hear. This weekend, they'll get a taste of what's to come.
When, where and how to watch
When: Saturday, September 11, 3:00PM BST
Where: Old Trafford
How to watch: Not televised in the UK
(All text odds are correct at time of publication and are subject to change)
Ronaldo's Manchester United debut back in 2003 ended in a 4-0 victory over Bolton Wanderers.
The Portuguese international was simply sensational on that occasion - that's despite coming off the bench as a substitute.
At the time, Ronaldo was just a teenager but as he prepared to make his debut, the Old Trafford crowd gave him a standing ovation. They knew he was the real deal. So did George Best who later said it was the most exciting debut that he'd ever seen.
After that, trophies and successes followed suit. During his time at the club, Ronaldo won three Premier League titles, one FA Cup, two League Cups, a Champions League, the FIFA Club World Cup and hey, even a Community Shield.
In 2009, CR7 left England and conquered the world. In 390 games away from United, the player scored 392 goals. And if that wasn't enough, he recently became the all-time highest goalscorer in international soccer; overtaking Ali Daei with 111 efforts.
So… what about Newcastle. Well, if the return of Ronaldo wasn't enough to worry about, Steve Bruce will be without star striker Callum Wilson and Ryan Fraser.
Both players have been ruled out with injuries while goalkeeper Karl Darlow continues his recovery from Covid-19 and could also miss out.
Bruce admitted that his side will be looking to spoil the party. But unless there's some other party going on in Salford, it's highly unlikely that the Magpies will spoil Ronaldo's homecoming.
With that in mind, we're going to go big in our first selection. Considering the first of Ronaldo's 48 career hat-tricks came against Newcastle, we're backing history to repeat itself at around the 13/2 mark.
Last three meetings
Man United 3-1 Newcastle (Premier League - February 21, 2021)
On their last visit to Old Trafford, the Magpies were sent home empty handed following a 3-1 loss.
Allan Saint-Maximin scored Newcastle's only goal in the opening half.
Newcastle 1-4 Man United (Premier League - November 17, 2020)
The previous head-to-head meeting at St. James' Park didn't go too well either for Steve Bruce.
Luke Shaw's own goal put the hosts ahead but that was as good as things got.
Goals from Harry Maguire, Bruno Fernandes, Aaron Wan-Bissaka and Rashford completed the job in the North East.
Man United 4-1 Newcastle (Premier League - December 26, 2019)
Man United fans were given the perfect Christmas gift when their side welcomed Newcastle to Old Trafford back in late 2019.
Again, it was the Magpies who struck first as Matty Longstaff opened the scoring. However, a brace from Anthony Martial and two further efforts from Mason Greenwood and Rashford secured another 4-1 win for United.
Last 10 head-to-heads
Man United wins: 6
Newcastle wins: 2
Man United goals: 23
Newcastle goals: 11
Expectations higher than ever
Should Cristiano Ronaldo play this weekend, he'll immediately break another record. The Portuguese international will close the longest gap between two Premier League appearances - which will be exactly 12 years and 118 days.
His last outing for the Red Devils was back in May 2009. It was goalless draw with Arsenal which closed the first chapter of Ronaldo's time at Old Trafford. That was also the game which sealed the club's 18th league title.
Speaking of titles, that is something that Man United fans will now be demanding.
Being the manager of that club is always going to come with a certain level of pressure. However, there is a feeling that the weight of expectations on Ole Gunnar Solskjaer is higher than at any other point of his managerial career.
A good result against Newcastle wouldn't necessarily alleviate that pressure, but it would continue United's growing momentum.
The Manchester outfit have only lost one of their past 36 home league games against the Magpies. What's more, the Red Devils have now scored in 14 successive Premier League home matches.
With that in mind, our second selection is for the hosts to score in both halves at around the 4/6 mark.
Major milestone for the Magpies
If not for Ronaldo, the major milestone of the day would have been Newcastle marking their 1000th Premier League game. The North East outfit are only the eighth team to reach that number.
Nevertheless, this may be a game to forget for the Magpies. Wilson, Fraser and Darlow aren't the only potential absentees this weekend as Miguel Almiron could also miss out.
The player was called up for international duty with Paraguay but the club - like many others in the Premier League - stopped him from travelling.
That is just another blow at a club which has an incredibly deflating aura about it.
All it took was 25 minutes before fans at St. James' Park began singing 'we want Brucie out' during the club's 2-2 draw with Southampton.
But then again, Bruce is not the only problem. The Magpies only made one permanent signing in this recent transfer window and the club responded by publishing a 768-word statement, outlining why that was the case.
Here at Planet Sport we prefer letters over numbers and the four that spring immediately to mind ahead of this game are BTTS.
Bruce might be missing a few players but he still has the likes of Joe Willock and Allan Saint-Maximin to his disposal. What's more, the Magpies have scored at least once in six of their last nine games with United.
We've already mention Cristiano Ronaldo as the main protagonist in this fixture.
But another Man United man to watch is Bruno Fernandes who has already scored three league goals this season.
The Portuguese international is currenlty available at 17/20 in the outright market.
From Newcastle's perspective, it's Dwight Gayle who leads the betting at 17/4. However, our pick is the aforementioned Allan Saint-Maximin who offers great value at around the 6/1 mark.