In the offseason:
David DeJesus (widely rumoured to be available throughout March)
Nori Aoki
Colby Rasmus
Will Venable
Seth Smith
I dunno, there's pretty much an endless supply of below-average LH outfielders available, you just might have to pay a few million $. After Gose was traded, one should have been acquired. You can't start a season with two possible replacement-level outfielders on the team and nobody in AAA. Well you can, but teams that do that aren't usually all that concerned about their win total.