That is my thought as well. If you have Pham, Benintendi, Fletcher on the roster, Pillar feels like a better 4th OF than Grossman. Grossman is not a good defender and while he does hit LHP well, so does Pham. I just don't feel like Grossman has much of a role once Pham is on the roster.
That being said, I wouldn't be surprised in the least to see them send Fletcher down for Pham and keep all the washed vets because White Sox.