Chelsea's head coach Jose Mourinho doubted the ability of Bayern Munich's coach, Josep Guardiola, to properly train the team ahead of the UEFA Super Cup match in Prague.
"Last year it was Jupp Heynckes' team, the best team in all of Europe. Now they have added new players and a new coach - I am not sure if they are still as good," said the Portuguese coach.
Bayern has been successful in the Bundesliga, however, in July they suffered a painful 2-4 defeat in the German Super Cup against Borussia Dortmund.
On Friday, the European giants will have the opportunity to compete for a prestigious trophy in the UEFA Super Cup match, which will be held in Monaco for the first time since 1998.
The fact that Bayern Munich lost all three finals they played will provide additional motivation for the club, while Chelsea's players triumphed in 1998 when they defeated Real Madrid 1-0.