At a glance, the A's seem ok at the big league level with not one useful catcher but two: Stephen Vogt and Josh Phegley may help to create the illusion that the A's need at catcher is not an urgent matter. The minor leagues tell a different story: you know you're in trouble when the headliners are journeyman Carson Blair (is it possible to bat .129/229/.226? Apparently it is) and Bruce Maxwell (now 25 and sporting a career slash line of .258/.339/.346 across A-AA).
In a way the A's recent trade of Jacob Nottingham was not a big blow to the catching depth chart, because even if he sticks at catcher Nottingham is unlikely to make an impact in the big leagues until mid-2017 at the soonest, more likely 2018. And the reality is that Oakland needs to solve its catching depth issue long before that.
Start with the fact that as great as he has been, Stephen Vogt is 31 and beat up. Coming off of surgery (elbow), and a magnet for vicious foul tips, Vogt's days as a primary catcher may be fewer than his days as a productive hitter. As he moves towards his mid-30s Vogt is hardly someone you can count on to start 120 games every year.
Meanwhile, as promising a season as Josh Phegley had he remains someone ill-suited to a primary catching position. Phegley struggled against RHPs, batting .220/.277/.431 against them last season, and while he has a tremendous throwing arm his catching and blocking skills leave much to be desired. He is an excellent back-up and platoon player but as a primary catcher his shortcoming would be oft exposed.
So right now the A's are a Vogt injury away from starting Phegley most every day and backing him up with Blair, a Phegley injury away from calling up Blair to catch often enough that Vogt doesn't wear down. More troubling is that as Vogt ages, there is nothing coming up through the pipeline any time soon.
In other words, the A's need to add a catcher to the organization, and unlike Nottingham it needs to be a catcher who will be ready in 2016, if needed, and certainly by 2017. That wasn't going to be Nottingham, and if the A's add a AAA or major league ready catcher they will be higher on the depth chart than Nottingham was anyway. Perhaps this was part of why Oakland felt it could deal Nottingham away -- yes it took their depth from "little" to "none" but the A's had to know that they needed to add a catcher to the system regardless, and that said catcher needed to be closer to the big leagues than Nottingham is.
I would be both surprised and dismayed if Oakland did not add a catcher to the organization prior to the start of the season, someone ready to catch in the big leagues this year. The question is whether it will be another "meh" backup catcher in the endless series of George Kottaras, Greg Myers, and Rob Bowen, or an actual mainstay who could contribute significantly to a playoff-caliber team.
If you're interested in being relevant, you should probably not be a wicked foul-tip away from starting Phegley and Blair behind the plate every day. I think the A's would be wise to invest in more than the usual journeyman-backup-catcher-who-has-been-with-16-organizations and to pay a bit -- be it in the form of money or talent -- to add catching depth at the highest level. Because Vogt isn't getting any younger or any less banged up, and Phegley likely isn't getting any better than his role as an excellent #2 catcher. And if Blair is the answer, honestly I'd prefer not to know the question.