Steve Yzerman stepped down as general manager of the Tampa Bay Lightning after building them into a perennial contender, handing the reins to longtime assistant Julien BriseBois just two days before training camp.

Yzerman will move to a senior adviser role working under BriseBois and he said he was "100 per cent committed" to the Lightning this season. Beyond that, Yzerman's future is cloudy and BriseBois is now in charge.

"I feel this change in role is important for me to allow me to spend more time with my family and to still make sure the Lightning is managed to the level everyone has come to expect," Yzerman said Tuesday. "We are all delighted that Julien is our next GM. He is more than ready."

It was a surprising move for a powerhouse team, one that reached the Eastern Conference final last season. The 53-year-old Yzerman spent the past eight seasons as Tampa Bay's GM, a tenure that included five playoff appearances, three trips to the conference final and an appearance in the 2015 Stanley Cup final.

He said he came to the decision in late July not to sign another contract as GM and that it took until now to iron out details on what to do next. Yzerman's family has remained in Detroit, and he commuted during his time on the job.

"We felt it was important to let everyone know what we were doing, end any potential speculation," Yzerman said. "We have a plan here. We come up with a plan, we like our plan, let's put it in place."

The plan is the 41-year-old BriseBois who had been an assistant to Yzerman since they joined the Lightning in 2010. For a number of years, he has been considered a future NHL general manager, and owner Jeff Vinik said the Lightning were lucky BriseBois wasn't hired by someone else.

Instead, BriseBois takes over a team that should contend for years to come.

"It will be business as usual for the Tampa Bay Lightning," BriseBois said. "The mission is going to be the same. That mission is to win the Stanley Cup."

Tampa Bay is again one of the Cup favourites based on Yzerman's stellar record of drafting, developing and acquiring players. He promoted Jon Cooper to head coach in 2013, re-signed captain Steven Stamkos and locked up defenceman Victor Hedman to a long-term deal in 2016. He also traded for J.T. Miller and Ryan McDonagh at last year's trade deadline and got Nikita Kucherov signed to an extension this summer.

Yzerman, a Hall of Fame centre with the Detroit Red Wings who won the Cup three times as a player, went into management immediately after retiring. He began his front-office career as vice-president of hockey operations under GM Ken Holland in Detroit and was part of a Cup winner in 2008 before getting the head job with the Lightning.

Holland signed a two-year contract extension at the end of last season to stay on as Red Wings GM.

Tampa Bay came two victories away from the second title in franchise history three years ago. Yzerman has also won Olympic gold medals in 2010 and 2014 as Canada's GM.

Yzerman went to Tampa Bay with a five-year plan to win a Cup. He leaves disappointed that didn't happen and hopeful it will under BriseBois.

"We got to Game 6 of the finals and we've gotten to three Game 7s of the conference finals," he said. "So hopefully it's this year. If not this year, beyond."