Reijnders joins City in a period which feels like a revolution rather than a renewal, and one that may require a revolving door at the Etihad over the next few months.
Attacking midfielder Cherki has already joined, while midfielders Kalvin Phillips, James McAtee and Jack Grealish have all been tipped to leave the club, along with defender Kyle Walker who spent the latter part of last season out on loan.
The squad also includes Ederson, Stefan Ortega, Nathan Ake and John Stones, whose futures have also been the topic of much media speculation.
Finding the right time to replace ageing stars like Ilkay Gundogan, Bernardo Silva and the injured Mateo Kovacic in City’s midfield will also surely be in Guardiola’s thinking.
Despite the £50m acquisition of Nico Gonzalez in February, the lack of running power and physicality in City’s engine room was exposed last season as they failed to win a major trophy for the first time in eight years.
Reijnders, who turns 27 in July, is viewed as the man to help alter that dynamic.
A powerful box-to-box midfielder, Reijnders ended last season with 10 goals and four assists in Serie A, with only one player in his position, Napoli’s Scott McTominay (16), having more goal involvements.
His performances were also considered one of the few positives in a disappointing season for Milan, who finished eighth in Serie A and missed out on European qualification.
Reijnders was ranked ninth for forward passes in Italy’s top flight last term and was fifth for through balls and carrying the ball.
“He will slot in very well at City, he runs a lot, he’s very willing to improve and he will love working with Guardiola,” said Italian football journalist Daniele Verri.
“He improved a lot since his first season at AC Milan.”