Triple-A Syracuse activated Hartwig (knee) from its 7-day injured list Tuesday and assigned him to Double-A Binghamton.
Hartwig had been on the shelf at Triple-A since mid-June with a torn meniscus in his left knee, but after making a full recovery from surgery, he was cleared to begin a rehab assignment at Single-A St. Lucie on July 30. After making two appearances, Hartwig was bumped up to Double-A, and he'll likely remain with Binghamton until a spot opens in the Triple-A bullpen. In his first appearance with Binghamton on Tuesday, Hartwig gave up one earned run on two hits and one walk while recording one out.