The 17-year-old will officially move to Anfield on July 1, joining the club’s Under-23 and Under-18 setup. Liverpool are expected to pay a compensation fee of around £200,000 to City.
Duncan, who has represented England at Under-17 level, announced earlier this week that he would be leaving City, where he has been since the age of 11.
The Huyton-born striker has been training with Wigan Athletic on his own after rejecting an offer of a professional contract at the Etihad Stadium, and becomes the latest high-profile youngster to walk away from the club in search of opportunities.
Duncan fired himself into the public eye in November 2016 when he became the first English player to score a hat-trick against Brazil at any level, doing so for the Under-16s in a 4-3 win over in Granja, the Brazilian national training complex.
He will join Liverpool’s Under-18s to begin with, linking up with new coach Barry Lewtas. Lewtas, of course, replaced Gerrard this summer after the Kop favourite moved to Rangers. He will join England Under-17 colleagues Luis Longstaff, Elijah Dixon-Bonner and Curtis Jones in a very promising group of young talent at the Academy.
Speaking previously about the influence of Gerrard on his young career, Duncan told the Liverpool Echo: I’ve always looked up to Steven. I’m related to him and like me he’s a local kid from Huyton.
“Steven’s been a big influence. What he achieved in his career inspires me. He always had that hunger and desire to win trophies. As well as talent, it was his attitude, character and leadership that made him the player he was.
“I’ve always tried to learn from him and when he messaged me after the hat-trick that meant a lot.”
Liverpool are set to confirm that another promising teenage striker, Rhian Brewster, has signed a professional contract after protracted negotiations with the 18-year-old.
Brewster has resisted offers from Germany to commit his future to the Reds, and will be fast-tracked into Jurgen Klopp’s first team upon his return from injury in August.