Lettieri, 22, skated in 38 games with the University of Minnesota Golden Gophers this season, registering 19 goals and 18 assists for 37 points, along with a plus-seven rating and 36 penalty minutes. He established collegiate career-highs in several categories in 2016-17, including games played, goals, assists, points, and plus/minus rating. Lettieri was named as an honorable mention to the All-Big Ten Team, and he was also University of Minnesota's selection for the Big Ten Sportsmanship Award. He led the Gophers in faceoff win percentage (55.1%; 268-for-486), ranked second on the team in goals, tied for second in shots on goal (132), ranked third in points, and tied for fifth in assists this season, and he helped the University of Minnesota win the Big Ten Regular Season Championship.
The 5-11, 195-pounder skated in 149 career collegiate games over four seasons with the University of Minnesota (2013-14 - 2016-17), registering 37 goals and 46 assists for 83 points, along with a plus-14 rating and 76 penalty minutes. Lettieri helped the Gophers win the Big Ten Regular Season Championship in each of his four seasons, and he played alongside current Rangers defenseman Brady Skjei for two seasons (2013-14 and 2014-15). In addition, the Excelsior, Minnesota, native helped the university of Minnesota win the Big Ten Tournament Championship in 2014-15. Over his final two seasons (2015-16 and 2016-17), Lettieri registered 63 points (26 goals, 37 assists) in 75 games, averaging 0.84 points per game over the span.
