Byers began his major junior career in 1981 with the Regina Pats of the Western Hockey League (WHL). The following year, the Boston Bruins selected him with a second-round pick (39th overall) at the 1982 NHL Entry Draft. Byers showed promise by scoring 32 goals in each of the next two seasons with the Pats, but it was his 153 and 154 penalty minutes (PIMs) in each of those seasons that would be a better measure of his future NHL career.