Boxberger (oblique) threw batting practice to fellow rehabber Kevin Kiermaier (wrist) on Wednesday, Marc Topkin of the Tampa Bay Times reports.
It was another step in the right direction for Boxberger, who's been progressively moving through the rehab process over the last several weeks. The 28-year-old closer was originally given a recovery timetable of 4-to-8 weeks, with the early end of that window having just recently passed. Boxberger remains without a more concrete return time frame, but he's at least emerged from each successive step in his recovery without setbacks.