The Philadelphia Phillies had reached an agreement to acquire veteran left-handed starter Tyler Anderson from the Pittsburgh Pirates, Jon Heyman of MLB Network reports. Two prospects -- right-hander Cristian Hernandez and catcher Abrahan Gutierrez -- were heading to Pittsburgh in the deal, though the trade has hit a snag, per Heyman.

The nature of the holdup is due to an issue with one of the minor leaguers heading to Pittsburgh in the deal, according to Ken Rosenthal of The Athletic. Anderson threw a bullpen session at PNC Park on Tuesday afternoon, reports Jason Mackey of the Pittsburgh Post-Gazette. It's unclear whether the Phillies can still complete the trade (perhaps with different prospects) or whether Pittsburgh will look to trade Anderson elsewhere.

Anderson, 31, is on a one-year contract and owed the balance of a $2.5 million salary for 2021. On the season, he's pitched to a 4.35 ERA with 86 strikeouts and 25 walks in 18 starts and 103 1/3 innings.