I already touched on the Salvador Perez injury a little here, but I don't think it can be overstated how much it hurts the Royals and their chances, however slight, to contend this year. It really puts the Royals at a disadvantage, especially compared to the other teams in the AL Central. Detroit (Alex Avila), Minnesota (Joe Mauer), Cleveland (Carlos Santana) and even Chicago (A.J. Pierzynski, no matter how much you despise him) are all ahead of the Royals' current situation, with Brayan Pena and Humberto Quintero splitting time until Perez is healthy again.
I believe if you looked up "indefatigable" in the dictionary, you would find a picture of Brayan Pena. Just in his time with the Royals, he has outlasted John Buck, Miguel Olivo, Jason Kendall, and Matt Treanor. This despite not being particularly gifted defensively, or even offensively. That's not to say he doesn't have his merits. Catcher defense is especially hard to quantify, but I do think his defensive shortcomings have been exaggerated somewhat. He has thrown out would-be base stealers at a better than league average rate all three seasons he's been a Royal. And he's not a great hitter, but he's not a complete embarrassment--he did post a 100 OPS+ in 2009, although that has dropped to 76 and 72 the last two years. So he could be adequate as a backup catcher, but starting him most of the time is a disadvantage for the Royals.
On the other hand, Humberto Quintero has a reputation as an excellent defensive catcher, but cannot hit a lick. Here's a guy who has compiled a lifetime OPS+ of 58, in the National League. That is terrible. For comparison, Jason Kendall's legendary 201o season with the Royals produced a 71 OPS+. And Quintero's 6 walks in 272 plate appearances last year (hitting 8th in an NL lineup, mind you) makes Yuniesky Betancourt look like Ted Williams when it comes to plate discipline.
The best-case scenario for the Royals here is that the best part of Pena's game and Quintero's game can somehow mesh and form a decent replacement until Perez is back. Essentially, the Royals need to tread water until then.
Up next: the starting rotation