Manchester City's Spanish coach Pep Guardiola (left) and Manchester City's English forward Raheem Sterling react during the UEFA Champions League final football match between Manchester City and Chelsea FC at the Dragao stadium in Porto on May 29, 2021. (JOSE COELHO / POOL / AFP)

Manchester City manager Pep Guardiola said he is saddened by the departure of Gabriel Jesus, Oleksandr Zinchenko and Raheem Sterling but that the revenue generated by their transfers had contributed to the club's sustainability.

In part I'm a little bit sad that these important players have gone ... But it's a business. To invest you have to sell players, otherwise you can't be sustainable. I know the image of the club is that always we buy, buy, buy. But we sell too. We sell important players for big money.

Pep Guardiola, Manchester City manager

The Premier League champions sold Jesus and Zinchenko to Arsenal for reported fees of 45 million pounds ($55 million) and 30 million pounds, respectively, in the close season window.

City, who have consistently ranked as one of the highest-spending clubs in European soccer in recent years, also let Sterling join Chelsea in a deal worth up to 50 million pounds.

ALSO READ: Sterling says goodbye to Man City before moves to Chelsea

They have fallen foul of UEFA's Financial Fair Play rules in the past, which were designed to curb excessive spending, although they limited their punishment by winning an appeal through the Court of Arbitration for Sport.

"In part I'm a little bit sad that these important players have gone," Guardiola told reporters ahead of City's Community Shield game against Liverpool later on Saturday.

"But it's a business. To invest you have to sell players, otherwise you can't be sustainable. I know the image of the club is that always we buy, buy, buy. But we sell too. We sell important players for big money.

Manchester City's head coach Pep Guardiola (left) interacts with player Gabriel Jesus at the end of the English Premier League soccer match between West Ham United and Manchester City at London stadium in London on May 15, 2022. (KIRSTY WIGGLESWORTH / AP)

"All the clubs know today selling players is not easy. All clubs want to do it but not everyone can."

READ MORE: Man City trounce Newcastle to open up three-point lead

City begin their Premier League title defence with a trip to West Ham United on Aug 7.