Helene St. James of the Detroit Free Press provided further details:
Yzerman earned enshrinement into the Hockey Hall of Fame for a playing career that featured three Stanley Cup championships and nine All-Star Game appearances across 22 years with the Detroit Red Wings.
The 53-year-old Wings legend joined the team's front office following his retirement in 2006. After working as the Hockey Canada executive director for the 2010 Winter Olympics, he was hired by the Lightning as their general manager in May 2010.
Tampa Bay, which missed the playoffs in each of the three seasons prior to his arrival, reached the postseason five times in his eight years as GM. That included three trips to the Eastern Conference Final and a Stanley Cup berth in 2015, when the Bolts lost to the Chicago Blackhawks in six games.
He's played an instrumental role in building one of the NHL's most talented rosters, led by winger Nikita Kucherov, center Steven Stamkos and defenseman Victor Hedman.
"It's enjoyable," Yzerman told reporters about the job in February. "It's exciting. It is kind of fun, I guess. But we're not doing it to have fun. It's a business for us."
A reason for his decision to step aside wasn't immediately announced.
BriseBois has operated as GM of the Norfolk Admirals and Syracuse Crunch, the organization's AHL affiliates, in addition to his duties as the Bolts assistant since 2010.