You’ve heard the Phillies talk a lot about hunting value at the margins, and Friday’s trade for lefty slugger Justin Bour is a perfect example of it. Two years ago, the Phillies traded Darin Ruf and Darnell Sweeney for veteran infielder Howie Kendrick, who spent four months in town before the Phillies traded him to the Washington Nationals for a fourth-year minor leaguer named McKenzie Mills. Now, Ruf is playing in Korea, Sweeney is playing in Triple-A, and Kendrick is on the 60-day DL with a ruptured Achilles. Mills, meanwhile, is headed to Miami in exchange for Bour, who should provide a significant upgrade to the Phillies bench when he isn’t providing a boost to their lineup at first base against righties.