What you need to know:
- The German was well aware of the fate that befalls managers who stumble from the day he walked into the Premier League club, initially handed a contract for just 18 months despite his pedigree.
- Chelsea won the Club World Cup, reached two domestic cup finals and finished in the top four of the Premier League last season despite the difficulties caused by the sanctions imposed on Abramovich, which affected the club's operations.
Chelsea are still adjusting to life under their new regime but the ruthless sacking of manager Thomas Tuchel shows the change of ownership has not ushered in an era of patience at Stamford Bridge.
The German was well aware of the fate that befalls managers who stumble from the day he walked into the Premier League club, initially handed a contract for just 18 months despite his pedigree.
"What does it change?" said Tuchel as he was unveiled in January 2021. "If they are not happy with me, they will sack me anyway."
A hire-and-fire culture became the norm during Roman Abramovich's spectacularly successful reign, which ended in May when Todd Boehly's consortium took over.
Tuchel earned himself a two-year contract extension after winning the Champions League in May 2021, a triumph that came just four months after he inherited a squad that was under-performing under Frank Lampard.
But less than 16 months after Chelsea overcame Manchester City in Porto, and after a big-spending transfer window at Stamford Bridge, he finds himself out of a job.
Boehly's group spent a world-record £4.25 billion ($4.9 billion) to buy Chelsea in May after Russian billionaire Abramovich announced he was selling the club shortly after Russia's invasion of Ukraine.
The following week Abramovich was hit with UK sanctions, with the government describing him as part of Russian President Vladimir Putin's inner circle.
The new regime splashed out more than £200 million on a list of high-profile players including Raheem Sterling, Kalidou Koulibaly, Marc Cucurella, Wesley Fofana and Pierre-Emerick Aubameyang.
And Tuchel appeared to have earned the trust of the new owners.
He pushed for the signing of Aubameyang after their time together at Borussia Dortmund and reportedly cooled Boehly's interest in Cristiano Ronaldo, who wanted to leave Manchester United.
Yet, just seven games into the new season, the 49-year-old has been cut loose after damaging defeats to Leeds, Southampton and Dinamo Zagreb.
In keeping with his time at Dortmund and Paris Saint-Germain, results have dipped after a bright start.
Chelsea won the Club World Cup, reached two domestic cup finals and finished in the top four of the Premier League last season despite the difficulties caused by the sanctions imposed on Abramovich, which affected the club's operations.
Yet the expected Premier League title challenge following the club-record £97-million signing of forward Romelu Lukaku never materialised.
Lukaku complained publicly of struggling to fit into Tuchel's preferred system and has been shipped back to Inter Milan on loan at huge cost to the Blues.
Reports in recent weeks suggested other attacking players were unhappy with Tuchel's methods, frustrated that they were not given the freedom to shine.
Kai Havertz, Christian Pulisic and Hakim Ziyech have all struggled to deliver on big transfer fees, while Timo Werner returned to RB Leipzig last month.
Scoring goals has been a persistent problem and the defensive solidity that was the hallmark of Tuchel's early success at the club has been absent this season.
Tuchel can point to an untimely injury to midfielder N'Golo Kante, a loss of form for goalkeeper Edouard Mendy and the need for time for the club's new signings to bed in.
But his own behaviour had grown more erratic as the pressure increased.
He was sent off for two physical confrontations with Tottenham boss Antonio Conte in a 2-2 draw last month and lambasted his players for a "soft mentality" in losing at Southampton.
A limp 1-0 defeat on Tuesday to a Zagreb side with a strikingly poor Champions League record was the final straw.
"We are clearly not where we need to be and where we can be," said Tuchel after the match.
Boehly has made the bold call that a man who has reached two Champions League finals with two different clubs in the past three seasons was the problem.
Now the pressure is on the American to make the right hire to turn his investment into results on the pitch.