Ok, so, Santana doesn't just play CF. He's plays corners too. If Santana was gone instead of Arcia, all that would mean is that Buxton and Kepler would be 1-2 for CF with Arcia taking a corner spot when he played (or LH DH). So, instead of Buxton, Santana, Kepler and Grossman, it'd be Buxton, Arcia, Kepler and Grossman. Leaves two people who can play CF and 4 OF who can play corner (with Rosario eventually, who can also play all 3 spots) It's not that hard to figure out why people are asking why are we keeping Santana over Arcia.