After being acquired from the Pittsburgh Penguins, it was very clear that Jeff Petry likely wouldn't be long for Montreal. After previously being traded last summer, the Canadiens acquired Petry to help facilitate the Erik Karlsson trade. It was very likely that at no point would Petry ever be required to report to Montreal.
Today the Montreal Canadiens announced that they had officially traded Petry to the Detroit Red Wings. The Red Wings were reportedly the preferred destination of the defender all along, who wanted to be closer to home.
In the deal the Canadiens acquire a 6'2 defensive defenseman who will likely make their opening day roster. Montreal will retain a little over $2,000,000 for the next 3 years.