A bewildered Pep Guardiola admitted he cannot explain why Manchester City are conceding so many goals after their latest hammering at Everton.

The defeat represented Guardiola’s heaviest in his eight-year career as a manager. Romelu Lukaku opened the scoring for Everton. Their second from Kevin Mirallas came at a vital time, just moments into the second half. Teenagers Tom Davies and Ademola Lookman sealed Everton’s biggest victory over City in 31 years.

The result means City are now 10 points behind Chelsea at the top of the Premier League table. Though Guardiola would not concede that City are out of the title race, there was an impression that he recognises there is much he needs to change.

“Ten points is a lot of points, of course,” he said. “We have to see. I spoke to my players over the last three weeks or month: focus on the next game and try to do our best. Then at the end of the season we will evaluate our levels and performances: how was the coaching, how the players were.”

City had chances before Everton took the lead. Guardiola believes his team are currently being punished for a lack of ruthlessness.

“It depends how we create,” he said. “If you score two or three goals in the first half, the consistency would be good. The West Ham game, we had two or three chances before we scored – like we did here. In the West Ham game we were not punished. Football depends the way you attack, being clinical; and having midfield players that are confident. If they don’t score, that can affect the way you think. It would be a huge mistake to blame one person for this. It is the first time in my life I have conceded a lot of goals; that never happened before. That is why I have to know the reason why.”

He continued: “Last season every team was inconsistent. This season the teams at the top are incredibly strong. Against Tottenham, they were much better but in the other games (where City have lost), I don’t feel the opponents have been much better. In football, like in basketball and tennis, you have to put the ball inside the net and to stop the opponent from doing that. You have to find a balance between how you create and how you defend; then it is much easier for the players.

“They suffer [at the moment]. But like I said many times, that will make us stronger in the future. Maybe not this season.”

Everton vs Manchester City player ratings Show all 22 1 /22 Everton vs Manchester City player ratings Everton vs Manchester City player ratings Joel Robles - 7 out of 10 Quick off his line when City got in behind the Everton defence in the first half. Getty Images Everton vs Manchester City player ratings Seamus Coleman - 7 out of 10 More restricted in his attacking than usual, but still managed to bag an injury time assist. Getty Images Everton vs Manchester City player ratings Leighton Baines - 7 out of 10 Creative in attack, resolute in defence. The wing-back remains a big part of Everton's team. Getty Images Everton vs Manchester City player ratings Ashley Williams - 7 out of 10 Covered well when De Bruyne peppered deliveries in from the left. AFP/Getty Images Everton vs Manchester City player ratings Ramiro Funes Mori - 6 out of 10 Frustrated Aguero for long periods although often found himself chasing runners behind. AFP/Getty Images Everton vs Manchester City player ratings Mason Holgate - 7 out of 10 Making only his 2nd Premier League start, the youngster showed maturity as part of a back three. Getty Images Everton vs Manchester City player ratings Gareth Barry - 7 out of 10 A big influence in midfield, he kept Everton's game simple but effective. AFP/Getty Images Everton vs Manchester City player ratings Tom Davies - 9 out of 10 A busy, bustling midfield display from the impressive youngster who capped a great performance with a great goal. Getty Images Everton vs Manchester City player ratings Kevin Mirallas - 8 out of 10 Terrorised the City defence and ended with a goal and assist to his name. Getty Images Everton vs Manchester City player ratings Ross Barkley - 7 out of 10 A more mature performance from the forward than of late, his pass for Mirallas' goal being a highlight. Getty Images Everton vs Manchester City player ratings Romelu Lukaku - 8 out of 10 Opened the scoring with an assured finish and kept City's centre-backs under pressure all game. AFP/Getty Images Everton vs Manchester City player ratings Claudio Bravo - 2 out of 10 A nightmare afternoon for the much-maligned goalkeeper who conceded four of the five on target shots he faced. AFP/Getty Images Everton vs Manchester City player ratings Bacary Sagna - 6 out of 10 An interesting outlet for City on the right, he nearly brought them level with a looping header at the end of the first half. AFP/Getty Images Everton vs Manchester City player ratings John Stones - 5 out of 10 A difficult return to his former club, his confidence suffered as his team leaked goals. Getty Images Everton vs Manchester City player ratings Nicolas Otamendi - 4 out of 10 Bullied by Lukaku, he let himself down with some preposterous playacting in injury time. Getty Images Everton vs Manchester City player ratings Gael Clichy - 5 out of 10 Patrolled the left flank, but was poor in possession. Getty Images Everton vs Manchester City player ratings Yaya Toure - 5 out of 10 Phoning it in. A player of his ability should be offering his side more. Getty Images Everton vs Manchester City player ratings Pablo Zabaleta - 5 out of 10 Started in midfield, the Argentine flew into tackles with normal gusto but lacked the awareness and creativity required. Getty Images Everton vs Manchester City player ratings Kevin De Bruyne - 7 out of 10 City's best performer, he troubled Everton down the left for long periods. Getty Images Everton vs Manchester City player ratings Raheem Sterling - 6 out of 10 Full of pace and energy, he should have had a first half penalty. Faded late on. Getty Images Everton vs Manchester City player ratings David Silva - 6 out of 10 Typically slick in his movement, particularly in the first half, but was often crowded out by Everton's defence. Getty Images Everton vs Manchester City player ratings Sergio Aguero - 5 out of 10 Always lively in and outside of the box, but had few opportunities to strike and grew frustrated. Getty Images

Ronald Koeman, the Everton manager, used to be Guardiola’s roommate at Barcelona. The questions directed at him revolved around the performance of 18-year-old Davies, who was named as man-of-the-match. He described Everton’s afternoon as “perfect.”

“He’s playing on a high level,” Koeman said of Davies. “He has an impact for the team and ok you don’t expect Tom will score every weekend but the level he showed, and real composure on the ball, that aggression, we need that - we need that from every player, if not, we can’t win against City because there is a difference in individual and football qualities in ball possession.”

City's players looked at a loss with how to deal with Everton (Getty)

“It’s not all about the young players,” Koeman added. “I like to bring in young players but of course you cannot play 11 20-year-old boys this afternoon. But they are for the future. If like Tom, like [Mason] Holgate, if they bring the performance and the level then I will be the first to put them on the list.