Additionally, blue-liner Ethan Bear was assigned to the AHL.
The 26-year-old suffered the injury while blocking a shot in the first period of Wednesday's season opener against the Vancouver Canucks. He logged 22:19 of ice time in the 3-2 win.
Larsson ranked third among Oilers defensemen in ice time in 2018-19, averaging 21:37 per game. He also recorded three goals and 20 points in 82 contests.
Bouchard, 19, registered one goal in seven games for the Oilers last season. Edmonton drafted the 6-foot-3 rearguard with the 10th overall pick in 2018.