Maybe it's because they realize TINSTAACP, or maybe it's because a year of Rod Barajas scared the **** out of them. Whatever the reason, the Pirates have spent the last couple years frantically compiling catching depth. Catchers develop slowly, they get hurt, they break down under the workload. All sorts of things. And counting on the free agent market to fill a vacancy isn't a good idea, Russell Martin notwithstanding. An outcome like Barajas, or Brian McCann if you have Yankee money, is exponentially more likely than one like Martin. So the Pirates have fortified themselves with depth.
To begin with, they have four catchers who can play credibly at the major league level now. Francisco Cervelli and Chris Stewart can't replace Martin, and Cervelli has had some defensive issues, but they both fit the Pirates' emphasis on pitch-framing and Cervelli can hit some. Tony Sanchez probably has more ceiling with the bat, especially if he continues to try to hit the ball the other way, but his throwing issues haven't disappeared. The real ceiling, though, belongs to Elias Diaz (pictured). He's probably ready defensively now. He's struggled some at the plate in AAA, but he's struck out only three times in 72 plate appearances, so there's no reason to think he won't adjust. These four should be able, in some combination, to give the Pirates no worse than solid catching for at least several years. Cervelli and Steward aren't even eligible for free agency until after the 2016 season, although the Pirates are unlikely to pay them both arbitration salaries through then.
The idea, of course, is to have a bridge to Reese McGuire. Taken in the first round in 2013, McGuire has been promoted aggressively, especially for a catcher. His bat hasn't caught up yet, but his defense draws raves. Like Diaz, McGuire hasn't struck out much, just six times in 81 plate appearances, so there's no reason to think the bat won't come around well enough to make him an above-average catcher in combination with his defensive skills.
The Pirates, though, didn't bank everything on McGuire. Last year, they drafted two college catchers, Taylor Gushue and Kevin Krause, in the first nine rounds. Neither is a premium defensive catcher, but both have power potential at the plate. Gushue, however, has struggled badly so far in low A, which isn't good for a player from a four-year college program. Krause showed impressive power in his debut last year, but he's currently getting treated for elbow problems in the hopes of avoiding Tommy John surgery. There's also Jin-De Jhang, who's stuck behind McGuire on the Bradenton depth chart. After a rough year last year, Jhang has spent most of this year hitting over .400 and didn't strike out until a few days ago. He's had to spend most of his time at DH, which is far from ideal because he had defensive issues in camp.
The Pirates also have a couple catchers slated for short-season ball who could develop into prospects. Danny Arribas has a solid, line-drive bat and good athleticism. Yoel Gonzalez is somewhat similar to the Diaz of several years ago, as he has strong defensive skills and a bat that needs to develop. He's still only 18.