After enduring offensive struggles with the Reading Fightin' Phils during June and July, Philadelphia Phillies top prospect Aidan Miller had his most successful month with Reading in August. As a result, the organization announced on Sept. 7 that the infielder was being promoted to Triple-A with the Lehigh Valley IronPigs.
Miller is one of Philadelphia's consensus top three prospects. Entering August, the shortstop had a slash line of .222/.343/.354 with an OPS of .697. He was in a slump in Double-A and on track to finish out his season with the Fightin' Phils. However, the former Phillies first-round pick in the 2023 MLB Draft displayed his potential in a big way during August.
The Phillies promoted Aidan Miller to the Lehigh Valley IronPigs after a torrid August in Double-A
Miller had his best month of the season as a hitter in August for Reading. His surge at the beginning of the month earned him Eastern League Player of the Week honors. He totaled a 1.083 OPS and a .348/.454/.629 slash line in 89 plate appearances.
The Dunedin, Florida, native continued his success for the Fightin' Phils in six contests during September. He had a .421/.607/.632 line with a 1.239 OPS this month before the news of his promotion to Triple-A.
NEWS: Aidan Miller has been promoted to AAA Lehigh Valley, according to @_chaseford of @milb_central. pic.twitter.com/0fimIe7z8A
— Phillies Tailgate (@PhilsTailgate) September 8, 2025
Miller's success during August, along with top pitching prospect Andrew Painter demonstrating inconsistencies with the IronPigs, prompted ESPN to move the shortstop to number one overall in their rankings of the best Phillies prospects.
The top young infielder in Philadelphia's organization demonstrated his improvement during August in piling up RBI. Miller finished with 11 RBI combined in June and July, but had 16 last month with the Fightin' Phils.
Miller finished with a slash line of .259/.382/.427 and an .809 OPS in 108 games with Reading. He demonstrated his speed on the basepaths with 52 stolen bases. The IronPigs have 12 contests remaining in their regular season schedule, and Miller will now get a chance to adjust to the level before the campaign wraps.
The IronPigs have an 81-55 record and trail the Scranton/Wilkes-Barre RailRiders by a half-game for first place in the International League's East Division. The two clubs next meet for a pivotal six contests from September 9-14 at PNC Field. Miller has the opportunity to continue his successful offensive stretch and help propel Lehigh Valley to the playoffs.
MLB Pipeline's number 47th prospect will have the challenge of transitioning his excellent hitting to Triple-A with the IronPigs. Miller may encounter difficulty initially down the stretch of the regular season. However, it is a good sign in his development that he has been promoted to Lehigh Valley. He may begin 2026 in Triple-A as well, bringing him one step closer to debuting in the Majors.