Pep Guardiola is largely hailed as the greatest football manager of the 21st century, having tasted vast amounts of success with Barcelona, Bayern Munich and Manchester City in a managerial career that has spanned close to 20 years, winning trebles at all but the German club.
Yet, despite another defeat to Real Madrid during the 2025/26 Champions League, making it just one win and four losses from five knockout clashes during his time at City, Guardiola has another club has the toughest challenge of his managerial career.
Indeed, Los Blancos are one of the most successful football clubs of all time. They have won a record 15 European Cups and most recently lifted the Champions League title in 2024. Guardiola met them at least twice a season during his legendary spell as Barcelona boss, but he claims an adversary for England has been far more difficult for him to conquer.
Guardiola Confirms his Toughest Managerial Challenge
Manchester City manager Pep Guardiola sitting at Craven Cottage.
Despite being beaten once again by Real Madrid in the Champions League Round of 16, Pep refused to admit that they were his most difficult challenge, instead claiming that Premier League rivals Liverpool took that crown.
Speaking after City's 2025/26 defeat over two legs, Guardiola said:
“Real Madrid have not been my biggest challenge. My biggest challenge has been Jurgen Klopp and Liverpool. Maybe you’re in Spain [journalists] and you didn’t notice... You have no idea what it was like to face Liverpool in those games, a great learning experience”.
Liverpool had Guardiola's number in the 2024/25 season as they claimed a second Premier League title, although any battle with Arne Slot does not compare to his time against former Reds manager Jurgen Klopp.
Klopp's heavy-metal football seemingly being the perfect foil for Pep's passing game, the German continually ran Guardiola close during his time as Anfield boss, including a 97-point haul compared to City's 98 in the 2018/19 campaign, and 92 compared to City's 93 in the 2021/22 season.
Klopp also broke up Guardiola's run of what would have been seven straight Premier League titles when the Reds lifted the English crown in 2019/20, as City came a distant second.
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Jurgen Klopp gives a thumb up in the stands at Anfield
Guardiola never faced Liverpool during his time at Barcelona, having to wait until his own move to England to step into the dugout at Anfield, where he faced a raucous crowd in both top-flight and continental games.
His overall record against Klopp's Reds stood at just seven wins in 22 games, with seven draws and eight losses to the Merseyside club.
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Guardiola's record is much better against Real Madrid with 14 wins from 30 games. Admittedly, 15 of his meetings came as Barcelona boss, losing just twice and winning nine of those battles in the Clasico - including a famous 6-2 victory at the Bernabeu during his first season in charge.
It's been tougher at City, though. Pep has lost six of 13 meetings, including five defeats from the last six.