Imai is expected to work in bulk relief behind opening pitcher Bryan King during Wednesday's game in San Francisco, Matt Kawahara of the Houston Chronicle reports.
The Astros haven't provided official word that Imai will pitch Wednesday, but he hasn't been used since Aug. 3 and didn't join the team's other relievers in the bullpen for Tuesday's 4-1 loss, which seemingly signaled that he was being saved for the series finale. Since being dropped from the rotation in late July, Imai has made two relief appearances and was sharp in his most recent outing, striking out five over three perfect innings. King will likely cover the first inning or two before giving way to Imai, who should be capable of providing a decent amount of length since he had only recently been removed from a starting role.