From his first managerial job in 1983, Rangnick has built a reputation for spotting young talent and bringing them to the world's attention.
The 63-year-old has made a career out of discovering gems before selling them on for profit. Now, however, the German manager finds himself in a far more powerful position.
With the January transfer window just around the corner, we have taken a look at Rangnick's greatest ever signings and ask whether those names could link up with their former manager at Old Trafford.
Erling Haaland (RB Salzburg)
Let's get the obvious one out of the way first.
Rangnick was not the manager of Red Bull Salzburg when the Austrian club signed Erling Haaland for £7million. Nevertheless, the German is still credited with getting the transfer over the line.
The current Man United boss was working as the director of football and it's fair to say that the signing of Haaland for a seven-figure sum is one of his crowning achievements.
The Norwegian forward currently boasts a market value of over £130million and his signature is being sought by many of Europe's big hitters.
However, now that United have attained the services of Rangnick, surely the chances of the 21-year-old arriving at Old Trafford are better than ever - even if he is a Leeds fan.
Sadio Mane (RB Salzburg)
Sadio Mane was relegated from Ligue 2 with Metz before being signed by Red Bull Salzburg in 2012. The Senegal international scored two goals in 22 games for the French side yet Rangnick was able to see past the numbers and signed the player for a bargain price of £3.6million.
With regards to a potential move to United, you'd be better off putting your money on Senegal winning the 2022 World Cup.
Timo Werner (RB Leipzig)
At the time, Werner was the club's most expensive signing but considering Rangnick's CV, the bosses at Red Bull trusted his instincts.
The youngster delivered in a big way as his haul of 94 goals across 158 games helped the club to a third-placed finish in the Bundesliga and a Champions League semi-final appearance.
If that wasn't enough, Leipzig bagged a cool £47million transfer fee from Chelsea in 2020.
With the 25-year-old struggling to find goals at Stamford Bridge, it's possible he could be on the move come the next transfer window. A move to United, though rumoured, looks unlikely.
Roberto Firmino (Hoffenheim)
Rangnick was the manager of Hoffenheim when he completed the transfer of Roberto Firmino from Brazilian side Figueirense.
The deal was signed and sealed in December 2010 but it wasn't delivered until January 1, 2011. When the forward arrived, Rangnick was already on his way out after falling out with the club over the sale of Luis Gustavo to Bayern Munich.
Nevertheless, Firmino made a big impression at Hoffenheim and after four seasons, he moved on to Liverpool for £29million in 2015. The rest, of course, is history.
Is there a chance we could see him work with Rangnick at United? As things stand, that's a firm no.
Joshua Kimmich (RB Leipzig)
Rangnick pulled off arguably the bargain of the century when he signed Joshua Kimmich in 2013. The 18-year-old cost RB Leipzig £450,000 as he made the move from VfB Stuttgart.
Within two years of the signing, Kimmich became a household name for Bayern Munich and the German national team.
The right-back is now 26 years old and already has six Bundesliga titles to his name as well as a Champions League winners medal.
So, could Rangnick lure him over to Old Trafford? The answer appears to be no. Kimmich signed a new deal with Bayern last August and looks intent on making more history with the Bavarians.
Marcel Sabitzer (RB Leipzig)
In 2014, Rangnick's eye for talent produced another stellar signing for the Red Bull brand.
Marcel Sabitzer was the man in question as he made the move from Rapid Vienna to RB Leipzig. However, before playing over in Germany, the midfielder was loaned out to Salzburg where he completed the 2014/15 season.
Following six successful years at Leipzig, the club cashed in on his talents with a £13.6million move to Bayern Munich.
The player has only made eight appearances for the Bavarians this season and a move to Old Trafford cannot be ruled out. January may come a little too soon for the Austrian but considering his Rangnick connection, this move could be on the cards further down the line.
Naby Keita (RB Leipzig)
Here's another high-quality midfielder who was brought into the Red Bull family by Rangnick.
The Guinea international made appearances for both Salzburg and Leipzig before being sold to Liverpool for £52million.
Rangnick was desperate to keep the player and his performances in the Bundesliga certainly underlined why. Injuries have plagued his time at Anfield though a move to United looks very unlikely.
David Alaba (Hoffenheim)
David Alaba was already on the books of Bayern Munich when he joined Rangnick's Hoffenheim side on loan in 2011.
The player has since become a household name in European soccer and United could certainly do with a player of his quality in defence.
A reunion with Rangnick seems unlikely though, as the Austrian has only just began a new journey with Real Madrid.
Dayot Upamecano (RB Salzburg)
Sticking with the defensive theme, what about Dayot Upamecano?
Just like other names on this list, the defender went from Salzburg to Leipzig to thrust himself into the limelight.
Rangnick's reputation for discovering gems was once again enhanced as the Frenchman joined Bayern Munich for around £40million - not a bad profit for the Red Bull brand considering they first signed him to Salzburg for £1.9million.
Man United are in need of a world-class centre-back but its difficult to see how Bayern would let this man go. Then again, you can never rule out Rangnick's magic.
Emile Smith Rowe (RB Leipzig)
Any Arsenal fan will tell you that Emile Smith Rowe is the real deal.
But before the youngster was setting north London alight, he did have a short loan spell with Rangnick's RB Leipzig.
With the player still injured at the time of the loan deal, Bundesliga fans never got to witness Smith Rowe in full flow, Nevertheless, the fact that he came on the radar of Ranginick tells you a lot about his eye for talent.