Murray, meeting with reporters two days after the Ducks were eliminated in a Game 7 Western Conference quarterfinal loss to Detroit, said Beauchemin had been playing with a torn anterior cruciate ligament in one of his knees during the series.
The 32-year-old blueliner, who still managed to score two goals and notch four assists, will need off-season surgery to repair the damage, Murray said.
The GM also revealed the nature of several other injuries sustained by Ducks players.
Forward Nick Bonino, who missed a month of playing time earlier in the campaign, was dealing with a torn hamstring, while Ryan Getzlaf, who missed three games late in the season, had sustained an ankle injury.
Celebrity Families of 2014 [PHOTOS]