Keith Hernandez’s mustache has rarely left its perch below his nose in his adult life. It is the thicker, longer cousin to his eyebrows, the hirsute geometric center of his face. His mustache is an entity and a signature. After years of renown, it was voted the top sports mustache of all time in a survey by the American Mustache Institute in 2007.
But now, the Hernandez mustache might have a month of life left in it.
He announced the possibility of shaving it last week on a Mets broadcast. But…