Highmore (upper body) was placed on injured reserve Monday, according to Bruce Garrioch of Postmedia.
Highmore will miss the beginning of the 2024-25 campaign after being injured during the preseason. His return timeline is unclear, but the 28-year-old forward will probably be reassigned to AHL Belleville once he's healthy. Highmore had nine goals and 31 points in 43 minor-league contests during the 2023-24 regular season.