Pep Guardiola has said Manchester City will not "waste energy" on the Carabao Cup this season and will instead focus on the Premier League and Champions League.

City booked their place in the fourth round of the competition with a 2-1 win over Championship side Watford on Tuesday.

But Guardiola has vowed to field his reserves in their next tie, citing an already packed fixture schedule. "The next round, I announce to you, I will play the second team," Guardiola said. "We are not going to waste energy, for sure."

Guardiola has taken the Carabao Cup seriously in the past and lifted the trophy four times in a row between 2018 and 2021.

But asked to face Watford just 48 hours after the 2-2 draw with Arsenal, the City boss made nine changes to his team including handing a debut to 16-year-old left-back Kaden Braithwaite and a competitive debut to 19-year-old midfielder Nico O'Reilly.

"The schedule is the schedule, we cannot handle it anyway," Guardiola said. "Today for [James] McAtee, Matheus [Nunes], Jack [Grealish], Phil [Foden], who didn't play [against Arsenal], the young lad, 16 years old, it's perfect.

"That's why it's a good competition, otherwise we wouldn't win four in a row."

Erling Haaland was given the night off against Watford while key players like Éderson, Rúben Dias and Bernardo Silva were named on the bench.

Guardiola insisted he still wants to win the Carabao Cup, but hinted that he will continue to leave out his first-team regulars as they chase a fifth successive Premier League title.

"We play to go through," he added. "We never throw a competition. Never. But we played 50 hours ago. I'm not going to [take] a risk with the Premier League and the Champions League in this competition."