The Pirates reassigned Plassmeyer to minor-league camp Sunday, Kevin Gorman of TribLive.com reports.
Plassmeyer signed a minor-league contract with the Pirates on Friday.
Plassmeyer cleared waivers and was outrighted to Triple-A Lehigh Valley on Monday.
Plassmeyer was optioned the Phillies' spring training complex Sunday.
The Phillies selected Plassmeyer from Triple-A Lehigh Valley to start the second game of Saturday's doubleheader against the Mets.
Plassmeyer is with the Phillies on Saturday and is expected to start the nightcap of the doubleheader against the Mets, Matt Gelb of The Athletic reports.
Plassmeyer (undisclosed) has turned in a 1.32 ERA, 0.88 WHIP and 16:5 K:BB across 13.2 innings in three appearances for Triple-A Lehigh Valley since being reinstated from the affiliate's 60-day injured list Aug. 27.
Plassmeyer (undisclosed) signed a minor-league contract with the Phillies on Friday, Scott Lauber of The Philadelphia Inquirer reports.
Plassmeyer was released by the Phillies on Tuesday.
Plassmeyer (undisclosed) was placed on the 7-day injured list Wednesday at Triple-A Lehigh Valley, Matt Gelb of The Athletic reports.