You can't really expect a player to know precisely enough their position and the angle of the shot to know if they should block it or not.
If you are a CB and you have a chance to make the block, you've got to go for it.
Some, inevitably, will deflect in.
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The midfield three has an awful lot of ground to cover when Juve, as was the case for large chunks of the second half, are basically playing with five at the back.