I won't say Guardiola is not successful in champions league football because he has won the Champions league trophy but not with Manchester City and currently in the Champions league he has another chance to make history but against a very tough opponent in Bayern Munich. It will be a test between Guardiola and Thomas Tuchel for who is the better coach.
He is not actually wrong about that. If he meant in the past or whole time and yeah pep has ever won UCL with his past club but if he means about this time and pep is a looser. This is the fact. The lost against chelsea was really hard to accept for manchester city.
If we are talking about this time he is with city and he is still a looser, so many times that pep was saying if his main target was UCL caused by this trophy is most difficult to achieve with manchester city.
If guardiola will able to make the current form of city to win UCL and that will be awesome thing. What ktc said was true. pep was able to win UCL when barcelona was in the golden era but he is so difficult to do that again after such era has gone.
Tuchel is also in the right way to win UCL for the second times.