A former first round pick now in his fourth CFL season, Coombs was enjoying a career year with the Argos, hauling in 47 passes for 426 yards and a touchdown in nine games.
Three of those receptions came during Saturday’s 38-6 win over the Montreal Alouettes before the 24-year-old sustained the injury and was forced to leave the game.
While Coombs’ injury is a setback for the Argos’ offence, they could be close to getting a key defensive cog back on the field. Trestman added Monday that CFL sack leader Victor Butler is working out after being sidelined since Week 5 — although he remains day to day.
Cleyon Laing and Akwasi Owusu-Ansah are also considered day to day with knee injuries.
The Argos, who lead the CFL East Division with a 4-5 record, are back in action on Saturday night when they visit Calgary’s McMahon Stadium.
Get all the top stories from across the league delivered to your inbox.