Edit: Something also to consider.....the move could also be to make room for the PTBNL in the DeRosa trade. There was already room for one player, but maybe they decided on the player AND will be calling up Marte. I mean, the PTBNL is likely to be a pitcher....and they released a pitcher.
Edit: Nevermind. Supposedly he was already off the 40-man roster. But the confusing part of that is there was never an official DFA. Back when the Indians added David Huff to the roster in mid-May they just took Kobayashi off the roster and outrighted him to the minors, which never happens as there is a waiver process usually when DFAing someone. 'Tis the confusion if he was on the 40-man still or not. Apologies. In any case, bottom line, Masa is still officially sayonara.;-)