Thomas Tuchel is a perfect 3-0 against Pep Guardiola and Manchester City since joining Chelsea, and another win in Saturday's clash will suggest that the balance of power has changed in English football.
What a difference nine months can make. On this day in January, former Blues boss Frank Lampard was 24 hours away from paying the ultimate price for falling out of the Premier League title race as Roman Abramovich and Marina Granovskaia once again embraced change and casted the club legend aside – a price paid by numerous Chelsea managers throughout the Russian billionaire's tenure at the club.
German boss Tuchel, himself recently discarded by French powerhouse Paris Saint-Germain, was quickly installed as Lampard's replacement – with Abramovich offering him just an 18-month contract, a safeguard, perhaps, against further tumult in the head coach's office.
Now, several months later, Chelsea are European champions and Tuchel was rewarded with a new multiple-year deal.
Tuchel's influence was almost immediately felt at Stamford Bridge. The club progressed unimpeded through the Champions League as well as securing the coveted top-four finish which seemed improbable under Lampard, but if there was to be a key signifier of the improvements made under the German's stewardship it was a trio of performances against Pep Guardiola's Premier League champions-in-waiting Manchester City.
The first, a win in the FA Cup semi-final, was quickly followed three weeks later by an away league win in Manchester, only for the two clubs to meet once more in the Champions League Final just on May 29, where Tuchel made it three wins from three on European football's biggest stage thanks to a single Kai Havertz goal.
And ahead of the latest meeting between two of world football's most well-regarded managers on Saturday afternoon, Tuchel and Chelsea can serve a significant warning that there has been a seismic shift atop the balance of power in English football.
It won't be easy. There have been several doomsday predictions surrounding Guardiola for much of his managerial career but the Spaniard has repeatedly shown a capacity to meet challenges head on. Last season saw his side win just six of their opening 13 games in the Premier League before winning 13 straight and taking the league title at a canter.
Tuchel, though, has shown that he is more than a match for Guardiola's tactical nous – and has overseen a revolution at Stamford Bridge as he coronated Lampard's underperforming stars into some of Europe's best players.
Chelsea have also reloaded up front, adding the goalscoring instincts of Romelu Lukaku to address some of last season's goalscoring woes – a contrast to Guardiola and Manchester City who came up short this summer in their unceasing pursuit of Tottenham's Harry Kane.
City have once again stuttered at the start of the Premier League campaign, losing to Tottenham and dropping two points against Southampton, while Tuchel's Chelsea have shone – conceding just one goal so far this season en route to four wins from five.
Another on Saturday – which would be Tuchel's fourth against Guardiola and Manchester City so far this year – wouldn't just confirm Chelsea as legitimate title contenders, it would also suggest that the Manchester club's status as league standouts is under serious threat.
Speaking to the media ahead of the game, Guardiola appeared to fire a shot across Tuchel's bow by saying that his side struggled with Chelsea's "long ball" style.
"They controlled all departments which is why it was difficult in the final of the Champions League against an exceptional team," he said.
"My impression is we played with a lot of courage with personality but unfortunately we could not do it with the counter-attacks, long balls, second balls were not good enough and they beat us."
Also on rt.com 'Are you sure of doing this?' Chelsea boss Thomas Tuchel reveals he questioned Abramovich's decision to fire 'true legend' LampardAnd as Tuchel told the media ahead of the game, another win would be a sign of the consistency he craves at the club.
"It's a six-pointer between two teams who are clearly rivals for the top four," he said of the clash.
"They are the example and they are the benchmark at this high level and I'm very happy that we are able to produce these kind of performances and results but we need to prove we can produce this with the same consistency.
"It doesn't take a miracle to beat City but it is absolutely necessary to bring out our best performance."
But Tuchel remained coy when he was asked point blank as to who was the better coach.
"This question does not even exist for me, so I cannot answer it. It's a question for you guys and you can endlessly debate."
One suspects Chelsea fans might do that for him if he can coax another three points from Guardiola's team on Saturday afternoon in London.
By John Balfe