I think HK is the one guy the O's would be OK including in a trade. I think Mayo is the guy people will want. If we are really going to get a huge upgrade, we are going to have to part with one of our big 3. Of those guys, I think Mayo is the one they'd reluctantly move.
I could see a scenario where HK & Mayo aren't on the roster at the end of the season. In that scenario Santander in RF on a one year deal next year wouldn't be awful.
If Elias can upgrade the team in a very meaningful way and not trade one of our big 3, I'll be very pleasantly surprised. I don't know if a HK + Povich + third tertiary piece is enough to get us what we want/need.