I don't recall anything about ligament damage being released, but stand corrected if you can point me in the right direction.
I'm not doubting his character, I don't know anything about him, in fact, his character is probably top drawer. But if it was an injury that was serious enough to rule him out for over a month and counting, I doubt he would've been able to play on. I reckon it's something else.
The club are secretive over injuries, but this definitely seems like a new one to me.
Maybe him playing on is part of the reason he has been out for a month.