Right-hander Jeff Karstens, who was acquired in the Xavier Nady trade, will join the Pirates on Monday. That will give the Pirates a full, 25-man roster.
Karstens will move into the starting rotation, replacing John Van Benschoten — whose days as a starter are over. Van Benschoten was sent to Triple-A Indianapolis, where he will work out of the bullpen from now on.
Righty Jason Davis, who today was called up from Indy, will initially work in long relief but could become a starter if Yoslan Herrera falters again.
Karstens could start Friday against the Chicago Cubs. However, with Thursday being an off day, the Pirates may shuffle their rotation.