Arianza is, IIRC, out of options. If they try to send him down, he might get claimed. I'm guessing Breslow or Tonkin is gone, based on usage, with Palka called up. While it would be great if they had a RH OF in AAA that was ready, they don't. Palka could DH while Grossman plays the OF, when an OF needs a day off. He could also play the OF if needed. If Park was healthy and playing well, I'd guess he comes up. I'm not surprised no move has been made, unless there is an injury or utter horribleness, I don't think teams make many moves in April.