Zastryzny (elbow) will begin a rehab assignment Tuesday with Triple-A Indianapolis, Kevin Gorman of TribLive.com reports.
Zastryzny made it through a string of bullpen sessions without issue and has been cleared again for live competition. Out since mid-April due to a diagnosis of elbow neuritis, the 31-year-old left-hander could return to the Pirates' bullpen in the early part of next week if all goes well on the farm.