I'd prefer to introduce you once this mission is complete. Throwing you both in halfway through a mission seems too chaotic and a bit too abrupt. Plus, I have plans on how events after this mission will play out, so I have ideas on how to intro both of your characters easily. 
It's just relying on people to get their reaction posts up, and I can keep the action moving with some momentum to get us through this scene and onto the next one.