Before the season I had Iannetta ranked the highest out of that group. He has started out slow, and only has 2 hits (both HR). He has 10Ks and 6BB in 24 AB, which means he is striking out a bit too much for my tastes. I think he has the most talent and best ability to put up top 5 catcher numbers this year, but you might want to rotate the hot hand until he starts to show signs of life.
This news is interesting...
With the injury to Vladamir Guerrero, Mike Scioscia has not ruled out using Mike Napoli as a designated hitter on days he does not catch.
The drawback on this is it would require recalling a third catcher. If the Angels go through with it, however, it would be a nice boost for Napoli owners.
That might make it useful to hang onto Napoli to see if he picks up more ABs, but remember to keep an eye on Iannetta.