Pop, 29, had a 3.68 ERA through 7.1 innings this season and worked as an opener Sunday against the Arizona Diamondbacks, permitting two earned runs over two innings in a 4-3 loss.
The Phillies have shuffled their bullpen frequently this week, recalling Seth Johnson and Chase Shugart while Jonathan Bowlan hit the IL. Griff McGarry was traded to the Dodgers, Yoniel Curet was claimed by the Tigers, and Backhus is the latest addition after unexpectedly breaking camp with Philadelphia and then being optioned when Orion Kerkering returned from injury.
Backhus joined the organization via trade with the Diamondbacks in the offseason, part of a lefty-heavy Opening Day bullpen that included Jose Alvarado, Tanner Banks, and Tim Mayza. He delivered seven spring innings with a 1.29 ERA to secure a roster spot, though his major-league results have not matched those early spring numbers.
In his season debut, Backhus allowed three earned runs in the ninth inning against the Texas Rangers, contributing to a 5-3 Phillies win. His return gives Philadelphia a more balanced, four-lefty bullpen look, even as the unit has posted a 4.64 ERA this season.
Pop began his big-league career with the Miami Marlins in 2021, appearing in 50 games with a 4.12 ERA. He was traded to the Toronto Blue Jays in 2022, finishing with a 4.89 ERA there, and later had brief stints with the Seattle Mariners and New York Mets. In 2025, he increased his slider usage to 26.2% (his highest since 2023), posting a 23.1% whiff rate and a 19.4% strikeout rate.
