Help us crowd-source this. If you know one, leave it in the comments, email me by clicking the button at the bottom of this post, or tweet me @sammillerbp. Citations preferred, but not necessary. Current emergency catchers only, please.
Angels: We don't know this one. Many speculations of C.J. Cron, who caught early in college, but a) long time ago, b) Cron can barely play first, c) he's giant and d) he has had leg injuries. Better speculation is David Freese, who "spent a few weeks learning how to catch" as a prospect in 2007, then served an inning as an emergency catcher in 2009, catching a pop-up for the final out of the Cardinals season.
A's: Were still thinking about it in spring training. Broadcast crew speculates Max Muncy, who caught in high school. Twist: It's actually Brett Lawrie, who was acquired for their previous emergency catcher.
Astros: Evan Gattis (Presumably)
Blue Jays: Josh Donaldson, at least according to an A's beat writer.
Cardinals: Pete Kozma, who practiced in spring training. (Future: Greg Garcia. Also: Dean Anna was the Yankees' emergency catcher last year.)
Diamondbacks: Cliff Pennington
Dodgers: Scott Van Slyke. Chris Hatcher's Twitter bio calls him "the backup to the backup catcher if need be," which is what we all call an emergency catcher, but I don't think he's serious. As for Van Slyke, "He said framing might be his biggest deficiency. But he’s not going to actively work to improve it." UPDATED: "Kike is the third stringer now." Makes you wonder what Van Slyke did to lose the job.
Indians: Carlos Santana (Presumably)
Mariners: Willie Bloomquist (based on very old information)
Mets: Eric Campbell practiced in spring training.
Nationals: Maybe Danny Espinosa or Tyler Moore. Not Bryce Harper or Jayson Werth, though each volunteered.
Orioles: Steve Pearce, who has never caught as a pro.
Pirates: Has been Neil Walker in the past; on the other hand, Walker has been explicitly ruled out in the past. Sean Rodriguez, now a Pirate, was always the Rays' emergency catcher, and appears to be the Pirates', too.
Rangers: "It is almost always the backup infielder and that is the case again. Adam Rosales."
Rays: Jake Elmore, who has filled the role for other teams too.
Reds: It's Kristopher Negron. This trumps speculation by a beat writer that it's "probably" Skip Schumaker, or possibly Zack Cozart, who says he can catch.
Red Sox: John Farrell just told reporters it's Mike Napoli "but we're trying to stay away from that," Brian MacPherson passes along. Pablo Sandoval has said it could be him. In the past he agreed to do it for the Giants, but seemingly unhappily, and the Giants at times named other emergency catchers instead of him.
Royals: Probably Mike Moustakas. Yost: "Moose caught in high school. It could be him."
Tigers: Andrew Romine and Hernan Perez. Victor Martinez is on the team, of course, but working both guys out at catcher suggests they really don't want to go to Martinez, even though he caught 17 innings last year.
Twins: Eduardo Escobar
White Sox: Conor Gillaspie. "White Sox manager Robin Ventura said the emergency catcher is usually the club's backup infielder or the third baseman, because people 'just presume that's the guy who can do it.'"
Yankees: Perhaps Garrett Jones in extreme extra innings. Perhaps Gregorio Petit, which seems to be the common speculation, even by beat writers. Brendan Ryan, who is currently on the DL, lobbied for the job when he was in Seattle (but was passed over). I still think we don't really know this one yet.