Honestly, I would not be surprised to see either of Perez/Pena traded just before or during Spring Training, especially if a veteran catcher is signed by Baltimore, to make room for Sisco.
The main thing that concerns me about O'Connor is his injury history. 2 hip surgeries and 2 back surgeries already, for a catcher. If they do take a flyer on him, he could be like Zach Kapstein (traded from Red Sox as a catcher, was converted to outfield with Frederick due to injuries.)