Callahan enters his second season with the program and first as Director of Hockey Operations in 2019-20. He was previously assistant coach of the Islanders Hockey Club in the United States Premier Hockey League (USPHL) and has worked private and group lessons of all ages.
Callahan played three seasons for the New Hampshire Junior Monarchs and one season for the Islanders Hockey Club. During his junior hockey career, he played in 109 games, recording 26 goals and 33 assists for 59 points and was a part of three Dineen Cup Championship squads.
Callahan continued his playing career at Division III Plymouth State University where he played four season with the Panthers. During his time at Plymouth, he was an assistant captain for two seasons, winning the MASCAC Championship his sophomore season and competing in the Division III NCAA Tournament.
Following his senior season in 2017, Callahan received the Webster Award, which is given to a member of the team for his dedication and leadership throughout the season.