I haven't seen any news on his ankle, I think they were up in the air on their 3 backups. Watching film of Brissett right now, LSU actually tried real hard to sign him and he came for a visit so LSU knows him pretty well. Watching HS film Brissett looks like a real cool cucumber in the pocket and is pretty accurate with his throws and has nice touch, the problem I do see with him is he has no real juice on the ball.
Both guys have good speed but are more a pocket passer type. Brissett actually uses his running ability to avoid the rush but he stays in the pocket. I would think they will get a steady dose of Mathieu off the corner.