[5] During the 2011–12 season with the Barons, Milano led the entire Tier 1 Elite Hockey League with 44 goals and 43 assists for 87 points through 40 games.

However, on August 16, 2014, Eagles' head coach Jerry York announced Milano had advised the team of his intention to sign a professional contract with the Blue Jackets, thus forgoing his college eligibility.

[13] On March 23, 2015, Milano concluded his OHL career and was assigned to the Blue Jackets American Hockey League (AHL) affiliate, the Springfield Falcons.

[15] Milano participated in the Blue Jackets training and development camp before being re-assigned to their new AHL affiliate, the Lake Erie Monsters, for the 2015–16 season.

[20] Although he was originally assigned to their newly named AHL affiliate, the Cleveland Monsters, to begin the season, Milano was recalled to the NHL on October 21.

[24] Milano made his season debut on November 9, playing on the second line alongside center Boone Jenner and right wing Cam Atkinson.

[31] While with the Blue Jackets, Milano made his Stanley Cup playoffs debut on April 16 during their first-round series against the Pittsburgh Penguins.

For the first time, he made the Blue Jackets roster directly out of training camp and immediately scored his first career NHL goal on October 6, 2017, in a 5-0 shut out of the Islanders.

[38] However, as injuries quickly began to befall the Blue Jackets lineup, Milano and forward Jordan Schroeder were recalled to the NHL on December 26 an emergency basis.

[40] His overall play earned him an extended stay in the Blue Jackets lineup as he replaced Boone Jenner on the left wing of the second line.

[41] However, he shortly thereafter suffered a torn oblique muscle during a game against the Toronto Maple Leafs on January 8 and was expected to miss four to six weeks to recover.

[46] As the Blue Jackets clinched a berth in the 2018 Stanley Cup playoffs, Milano finished the regular season with 14 goals and 22 points in 55 games.

Despite this, he was made a healthy scratch for Game 1 of the Stanley Cup first round against the Washington Capitals to make room for Foligno's return.

[51] Injuries severely limited Milano's playing ability with the Monsters and he finished the season with 11 goals and 13 assists for 24 points through 27 games.

[53] He recorded five goals and 13 assists for 18 points through 46 games with the Blue Jackets before being traded to the Anaheim Ducks in exchange for Devin Shore on February 24, 2020.

[55] Once the 2020–21 NHL season began, Milano was placed on the Ducks' top line alongside Ryan Getzlaf and Rickard Rakell.

[57] At the conclusion of the 2021–22 season and his contract with the Ducks, despite establishing new offensive career highs, Milano was not tendered a qualifying offer and was released as a free agent.

Recently he scored twice in a game against the Tampa bay lightning, breaking his previous single season goal record of 14, as he led the Capitals to another victory as they continue to fight for a playoff spot.

Charges were subsequently dropped in January 2020 after Greer and Milano paid an undisclosed amount for the victim's medical bills and completed community service.