If you can’t handle it, then go play somewhere else. Jeff Samardzija sent that message, knowing there’s always something to talk about with your Chicago Cubs, whether it’s second-guessing the manager, another Carlos Marmol meltdown, Ian Stewart’s Twitter account, the Wrigley Field renovation dance or empty threats to move to the suburbs. Starlin Castro is in the middle of it now, as the two-time All-Star shortstop dealing with failure for essentially the first time in his pro career. Castro’s not “The Lone Ranger” in all this, as manager Dale Sveum said after Thursday night’s 6-1 loss to the St. Louis Cardinals at Busch Stadium. But this comes with being one of the faces of the franchise, someone the marketing department once put on billboards opposite Derek Jeter. Castro had his shot against Lance Lynn and the Cardinals (47-26) with the bases loaded in the fifth inning and the Cubs (29-42) down by one run. After popping out to catcher Yadier Molina in foul territory, Castro didn’t flash the temper he’s shown over the years. Castro didn’t slam his bat or chuck his helmet in frustration. He simply took off his batting gloves, handed everything over to a batboy and walked back out to shortstop. “It’s tough, man, but I keep my mind positive,” Castro said. “I can take 700 at-bats (and) there’s almost four months left. Just stay aggressive and keep playing hard. Let’s see what happens. I know I’m working hard every day. I know I can get out of this.” Castro finished 0-for-4 with two strikeouts, watching his batting average fall to .232. This at the end of a road trip in which he went 4-for-30 and forced the manager to think about giving him a day off to watch from the bench. “By numbers alone, he’s regressed, there’s no question about it,” Sveum said. “You’re getting way, way down as far as all the other shortstops in baseball right now (offensively). He’s under a .600 OPS. That would go without saying that he’s regressed.” Castro’s .588 OPS ranks 19th out of the 20 qualified shortstops in the majors, which is not what the organization projected when he signed a seven-year, $60 million contract to become a foundation piece for Theo Epstein’s rebuilding project. “I just think he’s in a slump and he’s going to turn it around pretty soon,” Epstein said. “I feel bad for him that he’s going through this. Obviously, we’d love better production and we will get better production out of him going forward. But in a way, it shouldn’t be unexpected because baseball is a game of failure and then adjustments.