After starring for the Storm in the following two seasons, Brian was named to the OHL First All-Star team and represented Canada at the 1998 World Junior Championships.

In the 1999–2000 season, Brian made his NHL debut with the Colorado Avalanche, playing in a solitary game on January 9, 2000 against the Chicago Blackhawks.

After spending the majority of his 5-year tenure with Colorado splitting between the AHL and the NHL, Willsie was claimed by the Washington Capitals prior to the 2003–04 season on October 3, 2003.

[2] Willsie established himself with the Capitals scoring 15 points in 49 games in a season that was shortened with a concussion During the 2004–05 NHL lockout, Willsie had a brief stay with Slovenian team HDD Olimpija Ljubljana before he racked up a team-leading 24 goals along with 17 assists (41 points) in just 53 games played for Capitals affiliate, the Portland Pirates, in the AHL.

[7] Willsie played in four games with the Avalanche early in the 2009–10 season but primarily remained in the AHL to continue as captain of Lake Erie.

[9] Assigned to affiliate, the Hamilton Bulldogs, Willsie was named an alternate captain and concluded the 2011-12 season leading the team in scoring with 44 points in 68 games.

After spending the last four seasons primarily in the AHL, Willsie returned for his second tenure in Europe signing an initial try-out contract with Finnish team, TPS of the SM-liiga, on August 21, 2012.

[14] At the conclusion of the 2014–15 season in Sweden, Willsie opted to end his professional career and returned to work in the Colorado Avalanche organization in a consultancy player development role.