Nothing seems to faze Starlin Castro. Not getting to The Show some six weeks after his 20th birthday, without a single at-bat at Triple-A Iowa, and only 57 games at Double-A Tennessee. Not a regime change at Clark and Addison that had the front office wondering whether he could stay at shortstop. Not the shadow of a sexual-assault investigation. It doesn’t matter whether his manager is a future Hall of Famer (Lou Piniella), one-and-done (Mike Quade) or an old shortstop (Dale Sveum) telling him not to chase hits. It doesn’t matter that he’s playing for an iconic team in a major market where his mental lapses are amplified by talk radio, Twitter and Bobby Valentine. So Castro isn’t worried about the next big thing – Javier Baez, No. 16 on Baseball America’s list of the game’s top 100 prospects. “That’s business,” Castro said Tuesday. “I’m here right now and I like this team. I’m going to be on this team all my career. I know he got pretty good talent. Let’s see what happens.” Three years after Ryan Theriot reported to Fitch Park after losing an arbitration case and issuing his “come and get it” declaration, Castro has spoken with Baez and knows the 2011 first-round pick can play. But the 23-year-old All-Star shortstop is focusing on taking his game to the next level. “I see myself like my whole career is going to be at shortstop,” Castro said. “And I’m going to be a good shortstop, not (just any) shortstop. A shortstop that can win the Gold Glove, hit, everything.” At this time last year, Theo Epstein admitted, “it was a bit of an open question in the organization whether (Castro) could stay at shortstop long-term.”