Brubaker (arm) threw a live bullpen session Monday, Justice delos Santos of MLB.com reports.
The newly acquired Miguel Andujar stepped in to take swings against Brubaker, who completed his first live work since landing on the 15-day injured list Sept. 18 with right arm inflammation. Brubaker looks like he'll have a chance to return before the Pirates' season comes to a close Oct. 5, but he probably won't have enough time to build back up to a traditional starter's workload.