I've got to guess that the biggest push right now would be to acquire a better catcher and somehow move Wieters's money in some fashion. Sorting for catchers last season with at least 250 PA and wRC+ of over 100 shows the following available options (with slash line and wRC+ in parentheses):
Yasmani Grandal (.247/.308/.459 - 102) - Currently on trade block from Dodgers @ projected 7.7 Million in arbitration and controlled until end of 2018 season (MLBTR)
J.T. Realmuto - (.278/.332/.451 - 105) - Currently on trade block from Marlins @ projected 4.2 Million and controlled until end of 2020 season (MLBTR)
Alex Avila - (.264/.387/.447 - 124) - Currently a FA
You might add in the two Barves catchers as well:
Tyler Flowers - (.281/.378/.445 - 124) - Owed 4 Million in 2018 and a FA at end of season
Kurt Suzuki - (.283/.351/.536 - 129) - Owed 3.5 Million in 2018 abd a FA at end of season
Of those, both Suzuki and Flowers caught less than 90 games, and I wouldn't trust Suzuki's 2017 since he has had a pretty meh career up until last season. Flowers came into his own in Atlanta, and would make sense, but the issue with him is that he is only controlled until the end of the season. Same goes for Suzuki and Grandal.
Avila could make some sense, but has some major questions. He caught less than 80 games, has a HUGE strikeout problem, and basically was on fire from March through June, then collapsed entirely in July, had a decent August, than proceeded to fall fairly below average in September/October.
I think there is a package to deal for Realmuto, which would make good sense since he is controlled until 2020 and projects to be at least a league average bat with good defense, but awful framing skills, worse than Wieters bad. From BRef, it seems that LF is only slightly worse as a whole than C across the board.