Even a good lefty bat off the bench would help late in games when you start to care about L/R matchups more. Though most of our RHB's hit righties just fine
How long before some Twitter/radio/TV moron (thinking Jeff Blair, Tabler or Zaun here) brings up the fact that Tulowitzki "hasn't gotten it done in the post season" (where he owns a 211/.270/.351 slash line in 63 plate appearances)