2011-12: Willman played high school hockey in Massachusetts for Barnstable in Cape Cod. He scored 19 goals with 16 assists. Barnstable entered the MIAA South Division 1 tournament as the second seed and defeated Braintree, 3-2 in the quarterfinals before falling to eventual champion Marshfield by the same score.
2012-13: Willman played for Barnstable and was a team captain as a senior. In 21 games he scored 19 goals with 13 assists. Barnstable entered the MIAA South Division 1 as the fifth seed and fell to Norwood, 2-1, in the quarterfinals to finish the season 14-5-2.
2013-14: Willman attended Williston-Northampton Academy in Massachusetts as a post-graduate and played for the Springfield Rifles U18 midget team after an impressive summer in the Beantown Classic. He scored 21 goals with 23 assists in 25 games for Williston-Northampton and scored 5 goals with 13 assists and 6 penalty minutes in 11 games with the Rifles. In October he committed to playing college hockey at Brown University in 2014-15. Ranked 116th amongst North American skaters in the Central Scouting final rankings, he was selected by Buffalo in the fifth round (121st overall) in the 2014 NHL Draft.
2014-15: Willman was one of three Brown University freshmen to make his college hockey debut after being selected in the 2014 NHL Draft. Skating in 30 games for the Bears, he scored 1 goal with 2 assists and was -13 with 12 penalty minutes. Brown finished 13th ahead of only last-place Princeton in ECAC Hockey and was swept by eventual league champion Harvard in a best-of-three first-round series.
Willman is a late round project pick whose size and skating ability made him an intriguing option despite the fact that he had played just one year of prep school hockey after playing public school high school hockey in Massachusetts. He is a smooth skater with a flair for the offensive side of the game, Willman stepped into the Brown program as a freshman and should contribute more in terms of scoring as he adapts to the college game.
Willman gained valuable experience as a freshman at Brown in 2014-15, though his offensive numbers were fairly pedestrian. Part of one of the more heralded recruiting classes in Bears' history, he should gain confidence as he adds physical strength and learns more about tactical play under the tutelage of head coach Brendan Whittet and his staff. Willman made great strides after going from high school to prep hockey at Williston Northampton and both Brown and the Sabres are hoping that trajectory continues. Long-term he projects as a second or third line winger with some scoring ability. He will likely need most of his college career to reach that potential.