Rangnick changed the way Tuchel watched football when their paths first crossed

Manchester United's clash with Chelsea on Thursday may mean little for both sides on the pitch - but try telling that to the respective managers.

The match at Old Trafford pits master against apprentice as mentor Ralf Rangnick faces mentee Thomas Tuchel for the first time in the Premier League.

While the pair are friends rather than foes, Rangnick versus Tuchel nevertheless provides an intriguing sub-plot to an otherwise uninspiring fixture.

It will be the latest chapter in a fascinating relationship between the two renowned German coaches, which stretches back 25 years.

History

The year was 1997 when the two first crossed paths. Tuchel was playing for Ulm 1846, then managed by Rangnick, before he suffered a career-ending injury at the age of just 24.

Tuchel felt betrayed by football as he waited tables at the Radio Bar in Stuttgart, a washed-up pro with a dodgy knee cartilage when, three years after his stint as a player came to a premature end, Rangnick called him and offered him a job within the German team's youth academy.

While Tuchel has since admitted he was uncertain at first, he agreed to take up the role and it proved the catalyst for a coaching career that has - so far - yielded 10 major honours.

Nine years later, mentor and mentee sat in opposing dugouts for the first time as Tuchel's Mainz overcame Rangnick's Hoffenheim 2-1 in the 2009-10 Bundesliga season.

Tuchel has a clear advantage in their head-to-head, winning four of the five matches between the two. Three of those came against Hoffenheim, while Tuchel also beat Rangnick when his ex-boss was at Schalke.

Tuchel looked on the verge of a fifth win over Rangnick in August 2011 as his Mainz team took a 2-0 lead before Schalke fought back to claim all three points in what remains Rangnick's only victory over his former student.

The unavoidable links between them even sparked suggestions Rangnick could help bring Tuchel to Old Trafford to replace him as manager, although those rumours were quickly dismissed by the interim United boss.

Shortly after he was appointed at United, Rangnick revealed he had turned down the chance to work at Stamford Bridge ahead of Tuchel succeeding Frank Lampard as Chelsea manager in January 2021.

Thursday's meeting - their first head-to-head for 11 years - is likely to be the last game contested by the formidable pair as managers as Rangnick prepares to 'head upstairs' in a two-year consultancy role with United.

What they have said about each other

Tuchel's admiration for Rangnick is clear and he credits him for launching his career in management. In November, just before Michael Carrick took United to Stamford Bridge to face Chelsea, Tuchel gave a wide-ranging interview where he reflected on their past.

'He [Rangnick] was my coach as a player, and he guided us. He opened, really, [our] eyes for us because we believed at that time in Germany that defenders run behind the strikers,' Tuchel said.

'No matter where they go. They go to the toilet, you follow them! From that moment, it changed how I watched football games. He (Rangnick) opened the door.

'At some point, you have to go through the door and you are responsible to make the very best of opportunities for yourself.

'This is what I did, because I had people like Ralf who supported me, and so many more, starting with my father and everybody on the way from there in my life, which was then closely connected all the time to football. That's why I'm a lucky and a blessed person and happy and grateful for where I am.'

The love-in between the German duo continued in December, when Rangnick heaped praise on his protege after he took interim charge at Old Trafford.

'To do what Thomas did in four months at Chelsea was incredible,' said Rangnick. 'If anyone had told Marina (Granovskaia) or Roman (Abramovich) what would happen or they had looked into a crystal ball to see what would happen in the next four months…incredible.

'To win the Champions League, finish fourth in the league, and now be towards the top of the league with almost the same players, is a big achievement.

'I am not sure I can say that things will develop in the same way for me at Manchester United.'

For Rangnick and United, that has proven to be a frustratingly prescient comment.

Tuchel was also asked about Rangnick during his pre-United press conference on Wednesday. 'It's nice to see him always,' he said. 'It's tough to play against teams like his. We will maybe have time for a quick chat, five minutes, but contact is not on a daily or weekly basis.'

Coaching styles

It is not just Tuchel who Rangnick helped mould. Liverpool manager Jurgen Klopp and Bayern Munich's Julian Nagelsmann are also students of a 'visionary' once dubbed as the 'Godfather of Gegenpressing'.

Rangnick had long been a protagonist of the type of 'heavy-metal football' deployed by the likes of Klopp. Before arriving at Old Trafford, he favoured a high-pressing, counter-pressing, proactive and attacking system which he has used in a career spanning nearly 40 years.

The 63-year-old brought his famed 4-2-2-2 formation to United but quickly ditched it as he realised United's players were either incapable or unwilling - or both - to implement his philosophy.

Rangnick has since opted for a 4-2-3-1 in the majority of United's matches - the system that became a staple of Ole Gunnar Solskjaer's reign - demonstrating the flexibility and adaptability that is also a hallmark of Tuchel's tenure at Chelsea.

Tuchel's preferred formation has been the 3-4-3, or occasional 3-5-2, with emphasis on the full-backs providing the width and the holding midfielders - players Rangnick would love to have at Old Trafford - setting the base to launch attacks.

That becomes a 5-3-2 when Chelsea have their backs to the wall, but Tuchel has not been afraid to switch it up.

The Chelsea boss is considerably more animated on the touchline than his German counterpart, often berating either officials or his own players.

Both have been refreshingly honest in some of their press conferences this season. Rangnick recently claimed United need 'open-heart surgery' if their fortunes are to be transformed, while Tuchel has not been afraid to criticise his employers.

Chelsea's request to have their FA Cup quarter-final victory over Middlesbrough played behind closed doors following the Government sanctions on Roman Abramovich, and the Stamford Bridge pitch, are among the issues to have drawn the ire of Tuchel.

How the apprentice can overcome the master - again

Tuchel will fancy his chances of claiming a fifth win over his mentor when they meet in Manchester.

While Chelsea have hardly set the world alight in recent weeks, United are in disarray. They are hopelessly out of form, with their players - and fans - seemingly desperate for the season to end. It was not that long ago that Bruno Fernandes said United are 'fighting for nothing' in the remaining weeks of another troubled campaign.

Chelsea's league season is also pretty much done and dusted - even a catastrophe in their remaining matches is unlikely to prevent a top-four finish - and they have the FA Cup final with Liverpool to focus on.

Tuchel will be hoping his attackers can take advantage of a United defence which is desperately short of confidence and clean sheets.

Rangnick vowed to improve the backline when he took the United job but his charges have stopped their opponents from scoring in only one match since January 22 - the 0-0 draw with Watford on February 26.

Scoring goals has also been a problem for the Red Devils. Chelsea have not exactly been free-flowing but their last five matches have included a 6-0 thumping of Southampton and a 3-2 win over Real Madrid in the Bernabeu - although that result could not prevent the Blues from exiting the Champions League.

Neither United nor Chelsea will be relishing Thursday's encounter - but the opposing managers will at least have the sight of a familiar face as they go up against each other for just the sixth time.