He's under-performed offensively, but luckily half of his value comes from a skill that doesn't incorporate slumping.
There's been a lot said about Brian McCann's first half slump in his first year as a Yankee, and much of this talk implies that McCann is playing under his valuation, that the Yankees are paying too much for a catcher on the decline. So far this season McCann has hit .226/.286/.372 (80 wRC+) with eight home runs, the worst batting line since his injury maligned 2012 in which he hit 87 wRC+ and only put up 1.7 fWAR. Luckily, a catcher's value is not solely derived from his hitting ability. There have been numerous comments already about the positive rapport he has with the pitching staff, and his defense has been fantastic. How fantastic? By FanGraphs' Defensive Runs, Brian McCann is worth 5.7 runs, 6th among all catchers. There's another aspect of his game that is elite – pitch framing.
The Yankees, at least as of late, have valued pitch framing in catchers. The Yankees last had Russell Martin, who was one of the better steals in recent history, and his receiving abilities are now considered among the best in the game. Chris Stewart, though a pumpkin at the plate, was also a great pitch framer. While this skill is real and (generally) definable, the market undervalues it and attributes the "extra" strikes to the pitcher. The Yankees took advantage of that with their acquisition of McCann, a skill that could, and will, make up for his offensive losses.
To compare, here are Brian McCann's framing abilities in comparison to Chris Stewart in 2013 and Russell Martin in 2012, courtesy of Baseball Prospectus Catching stats:
| Year | Framing Runs/7000 | Framing Runs (Total) | |
| Russell Martin | 2012 | 23.0 | 29.9 |
| Chris Stewart | 2013 | 20.9 | 22.6 |
| Brian McCann | 2014 | 22.1 | 12.5 |
Brian McCann is currently around the same pace of framing runs as both Martin and Stewart, and looks to pick up about 20 runs when the season comes to a close. That's worth about 2.0 wins, which is technically already baked into the pitching staff's numbers, but it's still an example of his abilities. If you factor the Rest-of-Season projections where he is projected to finish about 100 wRC+ and 2.0 WAR, that would essentially make him a 4.0 WAR player--even while slumping for a large portion of the year so far.
McCann is currently getting paid $17 million for 2014, and even with this current slump, that's still a bargain. He is projected to finish the season at around 4.0 WAR if you include his pitching framing ability, which in reality would command about $28 million in a perfectly rational free agent market (where $/WAR = $7 million). While many could argue that the Yankees would have been better off just signing Russell Martin for 2013 (which is perfectly reasonable), the fact is that the market is so undervalued that the Yankees did not lose much. The Yankees are paying for a player that could produce his whole salary's value in three years of play, even if he doesn't hit as well as he should. Don't get wrapped in McCann's offensive slump, because most of his value lies elsewhere.