Undrafted, on June 30, 2013, Milner signed a one-year American Hockey League contract with the Bridgeport Sound Tigers, an affiliate of the New York Islanders.
[6] On August 19, 2014, Milner signed as a free agent to a one-year contract with the Quad City Mallards of the ECHL.
[8] As a free agent the following season, Milner joined his third AHL club, in agreeing to a one-year contract with the Hershey Bears on July 7, 2016.
Having provided the additional depth to the Capitals, Milner continued within the organization in agreeing to a one-year AHL contract with the Bears on May 28, 2019.
During the 2010 offseason, Milner and two other Freshman hockey players (Philip Samulesson and Patrick Wey) were involved in an accident when the SUV they were passengers in was hit by a trolley close to the South Street T-stop near Boston College.