MANCHESTER, England — Pep Guardiola made 10 changes to his team and Manchester City paid the price.

A 2-0 defeat to Bayer Leverkusen in the Champions League on Tuesday made it back-to-back losses for City and raised questions over Guardiola's decision to leave out so many of his star players — including top scorer Erling Haaland.

"I take absolutely full responsibility," the City manager said.

"It was too much. (It was) the first time in my life I've done it, and it was too much.

"I believe that the long season, (with games) every two days, three days, two days, three days, everybody has to be involved.

"But, seeing the result, maybe it was too much."

Guardiola acknowledged his mistake at halftime at the Etihad Stadium — making three substitutions after Leverkusen took a 1-0 lead into the break.

By the time he eventually sent for Haaland, the German team had doubled its advantage.

But even the introduction of his Norwegian goal machine couldn't turn the game in City's direction, making it five losses in all competitions this season and piling pressure on City's next Champions League fixture against Spanish giant Real Madrid on Dec 10.

The Spaniard defended his reasoning, pointing to the relentless schedule that includes domestic fixtures and international duty, particularly for Haaland, who shoulders the scoring load both for club and country.

"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 said.

"And, for the future, for the next games, we have Fulham, we have Sunderland, Real Madrid, a lot of games together.

"I cannot play Erling for 95 minutes all the time.

"I had the feeling, after the (international) break, it's now three months, four months until March, and there is no human being who can sustain it for that long."

Guardiola's sweeping changes to his lineup came after defeat to Newcastle in the Premier League over the weekend.

But his bold team selection backfired with City looking disjointed after so many changes.

It was the first time this season Haaland has been left out of the starting lineup for a game in the Premier League or Champions League. He has scored 22 goals for club and country.

"You never know what would happen in the game with other players. Everybody thinks with Erling, Bernie (Bernardo Silva) and the others we should be better, but I don't have the answers," Guardiola said.

Alejandro Grimaldo fired Leverkusen in front after 23 minutes and Patrik Schick headed in a second in the 54th.

"No matter who they put on the pitch, it's a quality team," Leverkusen coach Kasper Hjulmand said.

"It's a great team. No matter who played, I think we did well."

It was around this stage last season that City found itself deep into a losing run that ultimately ended its Premier League title defense and left Guardiola's men battling to make the playoffs in the Champions League.

Tuesday's game was only its first loss in the Champions League this term, but City could tumble down the standings depending on Wednesday's results.

Agencies