The Nerazzurri are set to sign the Italy international striker from Internacional, according to Goal.
The move will take place on Monday, and will reportedly involve a swap of targets, with the Nerazzu currently holding the 18-year-old midfielder in a contract that is set to expire in 2019.
The Bianconeri have had a busy transfer window, with Luka Modric and Andrea Ranocchia all joining the club.
Modric is now one of the most expensive signings in Serie A history, and his move to Juventus this summer will see him join the Italian side for a club record fee of £50 million.
Gabbianini, who made his Serie A debut in 2009, has scored 25 goals in the last two seasons for Internacion.
He made his debut in the Italian Super Cup in 2015 and has also been capped by Italy at the Under-20 level.
He also has experience of playing in the Champions League.
Gazzetta dello Sport claims that Gabbiani will sign a two-year deal worth £15 million.
Goal also says the deal could include a release clause worth up to £15m, and Goal also reports that the Nerazos are close to completing the signing of Luka Milivojevic.
The 24-year old Serbia international has spent the last three seasons at Inter Milan, scoring 18 goals in 52 appearances.
Internacions fans can also look forward to another season of success with the arrival of the new club’s new coach, Giampiero Ventura, who was previously the boss of the Neruzio di Trabajadores, where Gabbiamini played for the first two seasons.
The Nerazians have a lot of work to do to get back into the top-flight, and are set for a difficult time with the likes of Manchester United, Real Madrid and Juventus all chasing their tails.
However, the Neros should be back in the mix this year, with a win against Juventus and a draw with Roma all likely to see them qualify for the Champions league, and with another win against Napoli or Napoli potentially taking them into the quarterfinals.