Painter's MRI on March 3 revealed and a second opinion confirmed a proximal sprain — meaning he might not need surgery after he rests for a month, according to ESPN's Jeff Passan.
Painter, 19, was looking to make the Phillies' Opening Day rotation after being chosen No. 13 in the 2021 MLB Draft. He threw 29 pitches in a Grapefruit League game March 1, when he allowed one run and three hits in two innings, and he posted a 1.56 ERA in the minors last season.
Painter needed the initial MRI after coming to camp with a "tender" elbow.
"It's pretty mild," he said Friday. "It's just kind of something we're going to take cautiously and make sure we don't rush anything."
— Gregg Murphy (@GMurphPhils) March 10, 2023
The sprain is not considered significant, according to The Athletic's Matt Gelb, and Baseball Prospectus' Derek Rhoads believes Painter's injury is similar to the one Arizona Diamondbacks pitcher Zac Gallen suffered in the middle of the 2021 season. Gallen missed 40 days due to what the team also described as a minor UCL sprain before he returned to the starting rotation.
Painter's timetable makes it difficult for him to pitch for the Phillies before his 20th birthday on April 10. He would've been the first pitcher to make his major-league debut as a teenager since Toronto Blue Jays righty Elvis Luciano in 2019 and the fifth since 1995. A total of 81 other teenagers have pitched in the majors since 1961.