It's strange some here are surprised that he hits a rough patch. Of course he's aging but Casemiro being inconsistent, espectially in his passing, is actually a very normal thing considering it arrived regularly at Real Madrid. I wrote it before he arrived and was answered, after a couple of PL games "who doubted him he's absolutely world class". He is, when he's in a good mental and physical shape and in the champion's league, otherwise he sometimes has months when he seems he can't pass properly.
Doesn't change the fact that he was amazing during the 1st half of the season.