A person with direct knowledge of the decision told The Associated Press on Thursday that the Canadiens have placed the 39-year-old on waivers. The person spoke on the condition of anonymity because the Canadiens have not announced the move.
The abrupt decision comes three months after Montreal signed Streit to a one-year, $700,000 contract after he won a Stanley Cup with the Pittsburgh Penguins last season.
The Canadiens signed Streit in free agency to restock their depleted group of defenseman. Andrei Markov left to play in his native Russia, Alexei Emelin was claimed in the NHL expansion draft, and Nathan Beaulieu was traded to the Buffalo Sabres.
Streit had zero points in Montreal's first two games before being benched the next two in favor of Brandon Davidson, who was acquired in a trade with the Edmonton Oilers last season. The Canadiens' reformed defensive group also includes free-agent addition Karl Alzner and rookie Victor Mete.
Canadiens coach Claude Julien previously said patience was required to allow the players a chance to develop.
"We're going to be fine," Julien said following a 6-1 loss at Washington on Saturday. "A lot of new faces back there, and guys are just trying to get used to doing the right things and being in sync with each other."
This is Streit's second stint with Montreal after spending his first three NHL seasons with the Canadiens. He has topped 40 points in six of 11 seasons and overall has 96 goals and 338 assists in 786 games.
The Canadiens have been outscored 11-2 in losing three straight since a season-opening 3-2 shootout win at Buffalo.