Pep Guardiola believes that dropping Kalvin Phillips for being “overweight” has taught the Manchester City midfielder a valuable lesson – that he has to be “perfect” all year. Phillips returned from the World Cup in a condition unacceptable to the manager and was left out of City’s 3-2 Carabao Cup win over Liverpool on 22 December. Phillips, a £42m summer signing, was back in the squad for the 3-1 Premier League victory at Leeds six days later. Guardiola said the 27-year-old had acted in a positive way to being excluded. “He wants to change,” the City manager said. “It will maybe be a good lesson for him in the future. A footballer has to be perfect over 12 months. Perfect. “Even in the holidays, he has to be perfect. You have to be ready because this level is so demanding. You have to [be able to] play three games [a week], you have to be fit. If you are not fit, then nothing. But I said last week, he [has] improved his level.” Phillips was an 87th-minute substitute in Thursday’s 1-0 league victory at Chelsea. During the game he was taunted by the home support about his weight. “He has a sense of humour,” Guardiola added. “It was funny for the Chelsea fans.” City face Chelsea again in Sunday’s FA Cup third-round tie before travelling to Southampton three days later for a Carabao Cup quarter-final. Guardiola would not be drawn on whether Phillips would be give a first start since arriving at City. “I don’t know but for sure, the Carabao Cup, [if] he is going to play,” he said. “On Sunday, we will see. I had a feeling last week, he is back. I had a good feeling.” After signing from Leeds, Phillips made substitute appearances in August and September before a recurrence of a shoulder problem suffered at his former club forced surgery. He was ruled out for two months, playing only as a 50th-minute substitute in November’s 2-0 Carabao Cup win over Chelsea before Thursday. “Kalvin was injured for a long part of [last] season,” said Guardiola. “This is the truth. He came and after could not train, struggled, had the operation with the shoulder. We need Kalvin like we need all the players.” Guardiola is pleased with the form of John Stones, who has started the last six matches in the Premier League. “He was maybe my first or second signing when I arrived seven years ago,” he said. “I know him quite well. I know when he is stable at home, here, happy. What a player. He has had some ups and downs in the past, he has had some injuries but I would say this is part of the process to realise what he needs. He is still young [28].”