Or just not designed for twisting, turning and impact sports like football?
I watched the lad from Arsenal on the opening game of the season do his ACL under the most innocuous of circumstances. Then you have Gazza v Forest.
I know having done my knee (as I slid for a ball, the knee plugged and all my weight went through the joint) how unlucky a player can be.
I think he's being optimistic to feature again this season.