Various sources are reporting that Michael Crotta will make the 25-man roster. With Garrett Olson pretty much a lock after today's outing the 25-man is finalized. Chris Leroux will be sent to Indy and Jose Ascanio will most likely be put on the DL. He is out of options. Jose Veras will need to be added to the 40-man, so that will be worth keeping an eye on. I wouldn't be shocked if the Pirates designated Brian Burres for assignment to clear space. I feel comfortable that Burres would sail through waivers and with Owens and Morris in Indy I just don't see the need to have him around if, by some amazing chance, he gets claimed.
UPDATE: As Charlie correctly pointed out in the comments Burres was removed from the 40-man over the winter and signed to a minor league deal. I guess that would leave Aaron Thompson as the most likely candidate to be removed from the roster.