The Habs have had a rough training camp, with several players sustaining injuries, including a few long-term losses at the minor and junior levels. This is the situation on September 23.
Shoulder surgery
Addison last played on September 9 against the Ottawa Senators during the Rookie Tournament, but he claimed that the injury did not occur during this game. The rookies continued to hold their training camp after the tournament, so it’s possible that the injury occurred then.
He underwent shoulder surgery, and will miss the majority of what was to be his first season of professional hockey, projected to be out for six months.