Tomassoni was part of the coaching staff at Harvard for 17 years in various capacities and helped the team with its only national title in 1989.
After graduating in 1980 Tomassoni continued his involvement with hockey by becoming an assistant coach for Bill Cleary at Harvard in 1982.
[1] Tomassoni's arrival coincided with the Crimson's return to prominence as they began to make the NCAA Tournament annually.
As time went on Cleary began to rely on Tomassoni more heavily, promoting him to associate status and effectively turning over the recruiting responsibilities to him.
[2] Tomassoni was part of Harvard's national title team in 1989 and was named as head coach when Cleary became athletic director after the 1989-90 season.