Though offered an opportunity to remain in place, the Italian's No.2 becomes the first of an anticipated 10 departures from various levels of the coaching staff
As exclusively revealed by Goal.com, after the Italian boss's sacking on Monday night, his No.2 is expected to be the first of up to 10 departures from the coaching staff as the 2011-12 Premier League champions reorganise themselves.
City extended an invitation to Platt to remain at the Etihad Stadium but he elected not to take it.
"David was offered the opportunity to continue his work with us but has declined the invitation. He has decided to leave his role with his close friend, Roberto Mancini," read a statement on the club's official website.
"David has made a significant contribution to the club's success since joining in 2010 and we wish him well with his career, wherever that now takes him."
Brian Kidd took charge of City's Premier League trip to relegated Reading on Tuesday following the sacking of Mancini.