McCann still has power, but he's a league-average hitter by most measures, and has been since he came to the Yankees. He'll be 33 by opening day next year.
Nearly all catchers, even the great ones, are pretty much washed up by 33 or 34. Carlton Fisk, Jorge Posada and Gabby Hartnett are among the few who bucked that trend.
Johnny Bench, Yogi Berra, Mike Piazza, Gary Carter, Mickey Cochrane and Bill Dickey — all Hall-of-Famers — were all either no longer above-average offensively or no longer every-day catchers by their 34th birthdays.
Joe Mauer moved from catcher to first base at age 30.
Ivan Rodriguez caught nearly every day until he was almost 40, but had his last great offensive season at 32.
Roy Campanella had his last great year at 33 (he had two bad ones before his career-ending car accident at age 35).
Thurman Munson was essentially a league-average hitter with no power — and had been for almost two years — by the time of his death at age 32.
Russell Martin was great offensively at 31, pretty good at 32, and below average this year at 33.
It's a difficult position physically, even for the great ones.