Pirlo, 41, retired from professional football in 2017 after a glittering career that spanned over two decades, with 19 major titles to his name, including the 2006 FIFA World Cup.
Often described as the greatest deep-lying playmaker of all-time, Pirlo has now moved one step closer to the next stage of his career with the club's U-23 side.
The Italian giants who recently secured their ninth consecutive Serie A title confirmed his return via the club's official website, five years since he departed for an MLS adventure with New York City.
Clarence Seedorf - Japanese restaurant called 'Fingers'
Andrea Pirlo owns the Pratum Coller winery
Andres Iniesta - Bodega wines
Oliver Khan - Goalplay Application
Cristiano Ronaldo - CR7 fashion, cologne, underwear and hotels
Gerard Pique - Kerad Games company and shares in Bas Alimentaria meat industry
David Beckham - Self marketing empire with various branded businesses & club owner
Zlatan Ibrahimovic started his own mobile game and clothing business called A - Z
Genarro Gatusso owns a fish shop and restaurant
Phillip Lahm - Schneekoppe food, Sixtus health care and shares in German sports lottery
Rio Ferdinand owns a restaurant, clothing line and magazine.
Mathieu Flamini: Co-owner of GF Biochemicals now worth $28-billion.