Chaffee, 22, tallied 16 goals and 29 points through 30 games for the University of Massachusetts in 2019-20. The 6-foot winger amassed 47 goals and 95 points in 108 outings over three seasons with the program. He was named to the Hockey East All-Academic Team in both 2017 and 2019.
The NCAA season was officially canceled on March 12 due to the coronavirus pandemic.
Minnesota signed forward prospects Adam Beckman and Damien Giroux each to three-year, entry-level pacts on Monday.