This is a freakish thing: Johan Santana hurt his Achilles tendon when a ball hit him:
Johan Santana actually hurt himself when retrieving a ball that hit him. Felt something is his Achilles. Being checked out in Sarasota.
— Dan Connolly (@danconnollysun) June 6, 2014
I can’t tell from the context if it was a comebacker or if he was hit by a pitch. Of course, why a pitcher rehabbing an injury for an American League team would be batting is an open question.