Zastryzny was placed on the 15-day injured list with left forearm inflammation Friday, Kevin Gorman of TribLive.com reports.
Zastryzny will be out of commision for at least 15 days, so the Pirates selected the contract of Carmen Mlodzinski from Triple-A Indianapolis to replace him in the big-league bullpen Friday. Considering the injury is to Zastryzny's throwing arm, Pittsburgh will likely be cautious with his recovery.