For his career, Fuentes does have some decent numbers against righties, as well, which may make him an attractive candidate at face value. Digging a bit deeper, we see that righties have batted .233/.333/.416 against Fuentes over the past two seasons, taking him deep eleven times in only 262 AB. Those numbers aren't horrific per se, but they are trending downward. In short, Fuentes is a fine lefty specialist at this point in his career - he's probably a better option than either Logan or Feliciano in that regard. However, with Logan improving as the season wore on and Feliciano making a fair amount, it doesn't really make sense to bring another expensive LOOGY on-board.
