Donnarumma arrived from PSG to directly replace Ederson as City's senior goalkeeper.
Guardiola said: "Donnarumma is much better with his feet than people think.
"Clearly he doesn't have Ederson's long throw, but that's because no one else has that. But he's very, very good and clear-headed when he receives the ball, in his positioning, in his initial control.
"And in making the right decisions: he builds the play well."
The manager added, "He's a player we've been following for years. He can play on the right, left, and even as a center forward thanks to his speed. He uses both feet exceptionally well and knows the Premier League perfectly."
