City's ethos under Guardiola has been to play out from the back with Ederson, but on current evidence it appears unlikely that Donnarumma can build attacks and fizz passes into the midfield like the Brazilian could do so expertly.
Ederson's departure comes after eight years as undisputed number one, winning six league titles, the Champions League and revolutionising the role of a goalkeeper in the English top-flight by providing eight assists.
"The way Pep likes to play and what has made them one of the most successful team in Premier League history circulates around the goalkeeper Ederson and his incredible control of the ball," former City keeper Peter Schmeichel told BBC Radio 5 Live.
"When they play Man City, managers tell players not to put pressure on him, it is wasted energy. He can play the short game even in front to his own goal. Even under pressure, he can make an 80-yard pass. He has been an absolute threat.
"We don't know the situation. Have they fallen out? Did Ederson ask to leave? Trafford has had an opportunity but no-one can play like Ederson.
"Donnarumma had a really good season with PSG and was instrumental in PSG winning the Champions League. He is OK with his feet but he is not Ederson - no-one is Ederson."