Polanco was eligible to return Wednesday, but he is still in the early stages of his rehabilitation. Polanco took batting practice on the field early Wednesday afternoon, and he has been throwing. He is still limited to indoor conditioning work, including running on an underwater treadmill.

With 35 regular-season games remaining after Wednesday, Pittsburgh hopes to get Polanco back on the field before the end of the year.

Francisco Cervelli (left wrist inflammation) -- aka "Cisco" for Players Weekend -- should return soon. Cervelli took batting practice on the field Wednesday, and he has been catching bullpen sessions and hitting high-velocity pitches off a machine. He is eligible to come off the disabled list Thursday. Cervelli on Thursday will discuss his next step with the training staff and manager Clint Hurdle.

Reliever George Kontos (right groin strain) will resume throwing Friday in Cincinnati. The veteran right-hander expects to return some time around Aug. 30, when his mandatory 10-day stint on the DL ends. Right-hander Joaquin Benoit's left knee inflammation is a recurrence of a previous injury that sidelined him in June, Tomczyk said. Benoit will rest until Friday before being reassessed in Cincinnati.