Peralta (back) threw a bullpen session Thursday, Marly Rivera of ESPN.com reports.
Peralta has been on the injured list for a week and a half due to left thoracic spine tightness, but he's resumed mound work and felt good after Thursday's throwing session. The Yankees initially hoped that Peralta would be available for next week's series in Texas, and he'll likely be considered for activation as long as he continues to feel good.