Career
He played in the National Hockey League with the New York Rangers, Buffalo Sabres, Los Angeles Kings, Dallas Stars, and New York Islanders. In his National Hockey League career, Donnelly appeared in 465 games. He scored 114 goals and added 121 assists.
He is currently an amateur scout for the Kings covering Western North American Colleges.
In 1986, while playing for Michigan State University, Mike set the National Collegiate Athletic Association single season goals record with 59 goals, and that same year scored a total of 97 points which placed him 18th on the all-time points list for single season.