The 23-year-old had been considered one of the top pitching prospects in baseball since being selected with the 13th-overall pick in the 2021 draft.
But injuries delayed his arrival to the majors, with Painter finally breaking through this spring to earn a rotation spot with the Phillies.
Wednesday’s setback, however, continued what has been a difficult introduction to the big-leagues.
Painter now has a 7.06 ERA over 65.0 innings and 14 appearances this season.
His last four outings have been particularly concerning for Philadelphia, as Painter has surrendered 21 runs in 15 innings of work.