Casemiro the renowned medical professional? I thought you didn't want amateur hour?
The long layoff was due to his foot, not his knee, so it's irrelevant here.
But just to clarify, your expectation is that whenever one of our players is involved in a challenge that hurts them, they should be taken off, regardless of the player's own judgement as to whether they can play on, because it could potentially be more serious? If that's the case then at least your logic is consistent, but I'd suggest it isn't a very sustainable approach - we'll run out of subs quite quickly.