The New York Mets are shutting down left-hander Jose Quintana for three months after he was diagnosed with a stress fracture on the left side of his ribcage, the New York Post reported Monday.The Mets announced Quintana’s diagnosis last week.Quintana, 34, signed a two-year, $26 million deal with the Mets in December after going 6-7 with a 2.93 ERA in a combined 32 starts with the Pittsburgh Pirates and the St. Louis Cardinals last season.