Manchester City manager Pep Guardiola admitted responsibility for his team’s surprise 2-0 Champions League loss to Bayer Leverkusen on Tuesday, acknowledging that his decision to overhaul the starting lineup was a costly misjudgment.

Guardiola made 10 changes from the side that lost 2-1 to Newcastle United at the weekend, leaving out key players including striker Erling Haaland, who has 14 league goals this season—far more than any other City player.

“There were too many changes,” Guardiola said in his post-match press conference. “I believe that with a long season, games every two or three days, everyone has to be involved. But maybe it was too much, seeing the result. It’s the first time in my life I’ve done it, and I realised it was too much.”

The Spaniard defended his reasoning, citing the relentless schedule that includes domestic fixtures and international duty, particularly for Haaland, who carries the scoring burden for both City and Norway.

“I felt from my instinct, from my gut, the team is training well, they are incredible, good vibes. So let’s go, Champions League at home, we are in a good position,” Guardiola explained. “For the future, with Fulham, Sunderland, Real Madrid, a lot of games coming up, you cannot play Erling 95 minutes every match. After the international break, there is no human being who can sustain it for that long.”

Guardiola suggested the rotated side was too cautious under pressure. “I think they played to not make a mistake, and to avoid punishing the team. You are not free and relaxed,” he said.

The defeat ended City’s 23-game unbeaten home run in the Champions League group stage, leaving them sixth in their group with 10 points after five matches. The top eight teams after the group phase automatically progress to the last 16.

City’s next European assignment is a high-profile trip to Real Madrid on December 10. Guardiola remained calm about the implications of the defeat. “We have time to prepare for Madrid,” he said.