well, roughly 30% of MLB pitchers are left-handed. so a left-handed hitter is going to face a RH pitcher about 70% of the time.
ergo, I don't think they replace Kepler with a RH hitter. my guess - they start the season with Larnach in LF, Wallner in RF and Buxton (assuming he's healthy) in CF. Martin can be a RH hitting backup OF, or Castro for that matter.
they have RH bats in Lewis, Miranda, Correa (assuming he's healthy), Jeffers.
Castro and Lee are Switch-hitters.
If Santana wants to come back for a reasonable price, I'd bring him back. (another switch-hitter).
If Rocco has to have a RH bat off the bench, guys like Margot are always available.