Clement is cheap and hasn't really had much of a chance. There's a possibility he comes back next year as a cheap bench option if he shows something this year. Plus, once we add another lefty in Horwitz he might have a role to get some spot starts when one of our many fringe lefties is sitting.
Biggio would make less sense in that regard as he's also a fringe lefty. He's also starting to get expensive, I just don't see how he comes back next year with what he's due to get in arb.
Vogelbach could get the boot as well as whatever playing time he gets would likely be soaked up by Horwitz. He has been playing and batting cleanup though. Biggio hasn't really been playing at all.
Tough to say, I think Biggio is getting dumped but wouldn't be surprised if it's one of the other two either.