2010-11: Sullivan played for Avon Old Farms (CT) prep school. In 27 games, he scored 3 goals and added 12 assists for 15 points. Sullivan has committed to Yale University for the 2011-12 season.
2011-12: Sullivan played his senior year of hockey at the Avons Old Farms Prep school. The big defenseman work really hard on and off the ice to improve his strength and overall game. He finished the season, scoring seven goals along with nine assists while taking no penalties. Sullivan was named to the 2012 Boys' Hockey All-New England Team by the NESPAC coaches association.
Sullivan is a strong skater with good balance, and excellent physical conditioning. His biggest challenge will be to overcome what some scouts consider to be questionable hockey instincts, and learning to read the play, especially at faster pace.
Sullivan decommitted in January to play at Yale University after the Bulldogs’ coaches suggest a year of junior level hockey before joining their program. On May 14, he committed to play for Boston College after a scholarship opened up from the departure of Brian Dumoulin (PIT) for the professional ranks. Sullivan will play his freshman year at the NCAA level for the Eagles.