The Canadiens acquired Shea Weber from the Predators for PK Subban in an exchange of veteran defencemen who helped Canada beat Sweden for gold at the 2014 Sochi Olympics.
Subban won the Norris Trophy as the league's top defenceman in the NHL in 2013 and Weber is considered the best active defenceman in the league to have never won a Norris.
The 30-year-old Weber had spent the past 11 seasons with the Predators and has played in four All-Star Games.
He had 20 goals and 31 assists in 78 regular-season games this past season.
Weber has scored 40 or more points eight times and finished with seven points in 14 playoff game this year.
The 27-year-old Subban finished with six goals and 45 assists this past season.
Subban is heading into the third season of his eight-year $72-million contract.