If they hadn't stupidly announced Ender would be platooning with him and touted getting a controllable piece then there would be no face saving needed.
I doubt we can move Duvall this offseason. If Matt Adams couldn't be moved, no one will trade for Duvall. Any team who wants him will just wait for us to non-tender him and snatch him up for half the price they'd have to pay if they traded for him and tendered him a contract.