I don't think Pagan is necessary right now. See what we have in Coghlan, who *should* be a well above average LF (he's really just an emergency infielder).
There really shouldn't be any panic after 12 games, just concern over approach at the plate. Maybe the new high performance department workouts has guys feeling out of sorts or something, who knows. Maybe it's just a general slump. It seems like a LOT of the game's top sluggers are having really, really bad starts to the season.