By Alek Arend Just moments ago, the New York Giants announced that they are placing rookie offensive guard Marcus McKethan on the season-ending injured reserve. McKethan, a fifth-round pick out of North Carolina, reportedly suffered a season-ending ACL injury. An unfortunate setback for the talented rookie. “Giants placed rookie fifth-round pick, OL Marcus McKethan, on injured reserve due to an ACL injury,” said ESPN’s Adam Schefter. “G Marcus McKethan (ACL) has been placed on Reserve/Injured,” the team announced. “Bad news that was anticipated for Giants rookie OL Marcus McKethan: he’s been p…