The A’s will place All-Star closer Mason Miller on the 15-day injured list on Thursday with a fracture of the fifth metacarpal (pinky finger) in his left hand.

The non-pitching injury occurred when Miller awkwardly placed his hand on the training table while getting ready to perform an exercise in the trainers’ room inside the A’s clubhouse following Monday night’s 4-0 victory over the Astros. The right-hander closed out the win with a 1-2-3 ninth on 11 pitches.

Miller has emerged as the most electrifying closer in baseball this season, posting a 2.21 ERA in 34 appearances with 15 saves. The flamethrowing A’s rookie has struck out nearly half of his batters faced, leading all Major League relievers with 70 strikeouts in 40 2/3 innings. Miller has thrown a whopping 306 pitches of at least 100 mph or harder, by far the most in MLB.

Miller’s brilliance was on full display during the All-Star Game at Globe Life Field earlier this month, when he broke the record for the fastest pitch in All-Star Game history (since pitch-tracking began in 2008) and earned the win for the American League after a dominant perfect inning that included strikeouts of National League stars Shohei Ohtani and Trea Turner.

There is no timetable for Miller to return at this time. Despite being a rookie with five years of control after 2024, Miller’s name has increasingly been swirling around in trade rumors in recent weeks. The timing of the injury is significant in that he will be on the IL through the July 30 Trade Deadline.

During an appearance on A’s Cast earlier this week, A’s general manager David Forst hinted that the club could look to keep Miller and other top players beyond this season.

"We’ll be opportunistic,” Forst said. “We may do some things. But anyone who expects we’re going to continue to just move guys for prospects will probably be disappointed because there are guys here we think are part of the team beyond this year.”

Miller’s placement on the injured list opens up a spot on the active roster for Ross Stripling, who returned from the IL on Thursday to start Oakland’s series opener against the Angels at Angel Stadium.