Guardiola leaves Aguero on the bench in loss at Barcelona

Manchester City’s manager Pep Guardiola walks on the sidelines during a Champions League, Group C soccer match between Barcelona and Manchester City. AP

BARCELONA, Spain — Pep Guardiola’s decision to leave Sergio Aguero out of his Manchester City starting lineup Wednesday (Thursday Manila time) backfired badly in a 4-0 loss at Barcelona in the Champions League.

Premier League-leading City failed to fill the void created by the absence of its top scorer. Barcelona capitalized and seized its opportunities, with Lionel Messi scoring three goals and setting up Neymar for another.

The loss at Camp Nou against Guardiola’s former team exposed two of the manager’s most important decisions as being off the mark.

Aguero’s exclusion was tactical. But another big factor in the loss will revive doubts about getting rid of England goalkeeper Joe Hart.

Despite scoring five goals in six Premier League matches and another six goals in Champions League qualifying and group phase matches this season, Aguero watched from the dugout as Barcelona took control of Group C with a commanding victory.

Guardiola instead resorted to a formation he used often at Barcelona, playing without a clear striker and instead aligning Kevin De Bruyne up front as a “false 9” with wingers Manuel “Nolito” Agudo and Raheem Sterling.

“It was my decision. I wanted more midfielders,” said Guardiola, confirming that Aguero was not troubled by any lingering injuries from recent international duty.

De Bruyne was the only City player to occasionally threaten Barcelona’s goal. His best opportunity came late with Barcelona already three goals clear, but goalkeeper Marc-Andre Ter Stegen did well to stop him one-on-one.

Another issue highlighted in City’s fourth consecutive game without a win was the poor form of goalkeeper Claudio Bravo.

Bravo, who Guardiola pushed City to sign from Barcelona at the start of the season, was sent off in the 53rd minute after back-to-back errors. Bravo first flubbed a pass right to Barcelona’s Luis Suarez and then used his hands to block his shot while outside the box, earning a red card.

Guardiola acknowledged that the mistake, which occurred when his team was trailing by a goal, crushed any chances of a comeback. Even so, he defended his goalkeeper.

“He knows what he did,” Guardiola said. “He has a lot of experience. He has been one of the best goalkeepers in the world for the past 10 years. I have no doubts in him.”