Anderson was seen throwing in the Pirates' bullpen before Tuesday's game, as his trade to Philadelphia doesn't appear to have gone through yet, Alex Stumpf of DKPittsburghSports.com reports.
According to Ken Rosenthal of The Athletic, an issue cropped up with one of the two players being sent to Pittsburgh in the agreement -- Cristian Hernandez or Abrahan Gutierrez -- leaving Anderson's status in flux until the issue is rectified or the deal is nixed altogether. More details about the trade figure to become available later Tuesday.