In Man City news, Phillips joined City from the Elland Road outfit in the summer of 2022. Despite his £45m fee, the 27-year-old will start for only the fifth time for City when they take on Newcastle in the EFL Cup at St James' Park on Wednesday.
"Marcelo [Bielsa] gave Kalvin the best of Kalvin in his career," said Guardiola.
A hero at his hometown club, Phillips became an England international under Bielsa's stewardship when Leeds were still in the Championship.
He went on to become a key figure in the side that finished ninth on their return to the Premier League and then started for England as they reached the Euro 2020 final.
"I'd love to have done with Kalvin what Marcelo has done to him. We have our own specific way to play and [he] sometimes struggles in a few things, while the previous [Leeds playing style] was perfect [for him]," added Guardiola.
Phillips' lack of involvement is even more stark given two of his previous four starts came at the end of last season, after City had already secured their third successive Premier League title.
In other Man City news, but with fellow holding midfielder Rodri suspended for three matches following his red card for violent conduct against Nottingham Forest, Phillips finally has a chance to play a meaningful role under Guardiola after turning down the opportunity to leave the club in the summer.
"The club spoke with him because he did not have many minutes," said Guardiola. "He said 'no, I want to stay'.
"We brought Kalvin here for his quality. He is open minded, always wants to learn and wants to help. This is what we want to try to do."
Meanwhile, Guardiola has revealed City will drive back from Newcastle after encountering travel issues.
In the past, City have flown the 150 mile journey from the north east.
In other Man City news, whilst club sources told BBC Sport that was not going to be the plan on this occasion, Guardiola appeared confused about the reasoning for what is likely to end up being a 3am return at the start of four away games in a row, including next week's Champions League trip to RB Leipzig.
"I don't know what happened," he said. "The travel manager told me. We cannot come back by plane because we don't have a plane to travel back.
"We have to take a bus. It's not a problem but we arrive so late, two or three hours later [than by plane].
"Then Friday we have to travel to Wolves and then we go to Germany to play Champions League for a really important game."
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