Tuchel again jeopardizes Man City's chances of winning the Champions League.

In 2021, during City's first and only trip to the Champions League final, Tuchel triumphed as Chelsea's manager.

Guardiola also came the closest to winning his third European Cup as a coach in 10 attempts while working for Barcelona, Bayern, and City.

Because of coronavirus limitations, Chelsea's 1-0 victory in front of a nearly empty Stadium do Dragao in Porto two years ago was a case of the apprentice surpassing the master.

As Guardiola's strong Barcelona team won 14 championships in four years, from 2008 to 2012, including two Champions League crowns, Tuchel, then a novice coach, observed and adored them.

While Guardiola was in command of Bayern for three years and Tuchel was in charge of Mainz and subsequently Borussia Dortmund, their paths eventually collided.

Two devoted football fans, the two even carried on a late-night conversation at a Munich bar in 2014 while imitating formations with glasses and salt and pepper shakers.

Before to the 2021 Champions League final, Tuchel remarked, "I was such a tremendous admirer of Pep when he was a player, and then when he became a coach it was like learning on the job for me.

Since there was so much to learn, I don't believe I missed a single game of Guardiola's Barcelona while I was an academy coach or coaching in the Bundesliga with Mainz.

There is mutual respect. Tuchel is "one of the few coaches I learn from to evolve (into) a better manager myself," Guardiola said of him last season.

Champions League history

In conflicts between the two, Guardiola has frequently prevailed.

In ten encounters between the two coaches, Guardiola has six triumphs to Tuchel's three over Chelsea during the course of a six-week period at the end of the 2020–21 campaign. Yet he won the most significant one, and Bayern's desire to hire him and fire Julian Nagelsmann in a shocking move last month was greatly influenced by his Champions League pedigree. Also, Tuchel led Paris Saint-Germain to their first-ever club championship final in 2020 and eventual champion Real Madrid to extra time in the quarterfinals of the Champions League last year despite Chelsea being in turmoil due to the fines placed on then-owner Roman Abramovich.

The 49-year-old now faces the challenge of taking Bayern back to Champions League triumph where Guardiola failed.

The City boss, though, bears a much greater burden of expectation.

Guardiola, who is in his seventh season with Manchester, is vying for a fifth Premier League championship.

Nevertheless his record is still marred by his inability to cross the finish line in Europe.

Guardiola emphasized the significance of winning the Champions League to his legacy at the Etihad Stadium. "That doesn't mean I agree with it, but without a doubt we will be judged by this competition," he said.

Erling Haaland's arrival puts even more pressure on Guardiola to complete the task this year. 

In a 4-1 victory over Southampton on Saturday, the Norwegian scored twice after returning from injury, bringing his season total to 44 goals.

Guardiola compared his top striker Cristiano Ronaldo to Lionel Messi in light of those statistics.

But the reason City had to defeat rival teams from around Europe to secure Haaland was to make the difference when the Champions League's razor-thin margins mattered most.

In 25 Champions League matches, the 22-year-old has scored 33 goals, including five in a 7-0 demolition of RB Leipzig in the round of 16.