For better or for worse, the offensive expectations for catchers are lower than the other positions. The justification is usually that catching is the hardest position; besides the obvious physical wear on their knees, they’re tasked with calling pitches throughout a given game, working with a diverse pitching staff on strategy and planning, and taking plenty of foul balls off of the rest of their body. Throw hitting Major League pitching into all of that? Quite a tall order - in fact, only eleven teams’ catching corps have put up a wRC+ over 100 so far in 2021.
With all that being said, the Mariners currently own the second-lowest catcher wRC+ in baseball at just 44, ahead of only the Rockies’ 29.