Maccagnan: Zac Stacy trade not related to concerns about Stevan Ridley’s knee

Instead of taking a shot on a rookie running back with a seventh-round pick on Saturday, the Jets opted to trade it to the Rams in exchange for Zac Stacy. Stacy, a 2013 fifth-round pick, became an odd man out in St. Louis when the team drafted Todd Gurley in the first round on Thursday. Reports…