Phillies top prospect Aidan Miller to have back procedure, could miss 6-8 weeks

The mystery surrounding Phillies top prospect Aidan Miller's lingering back injury now has some clarity.

Miller was diagnosed with discogenic pain and facet inflammation in his lumbar spine and will undergo a "minimally invasive" back procedure this week, the Phillies said Wednesday.

The 21-year-old could return in six to eight weeks, the organization said, which would align with some time in late July or early August.

The Phillies said Miller will undergo a procedure called radiofrequency ablation of the facet joints on Friday. He will then rest for one week before resuming his rehab, according to the club's statement.

Radiofrequency ablation uses radio waves through a needle to heat an area of the nerve to prevent pain signals from being sent to the brain, according to the National Library of Medicine.

"The benefits of RF are the following: it is safer than surgery; it doesn't need general anesthesia, by that means diminishing the complications; it causes pain alleviation for a minimum of 3-4 months; it can be repeated if needed; it improves joint function; and it minimizes the necessity for oral pain treatment," the NLM's website says.

Miller appeared on the fast track to making his big league debut at some point this season after his climb to Triple A in 2025. But a back injury kept him off the field during spring training and has kept him from playing at all this season.

The Phillies said Miller saw spine specialists after he dealt with recurring lower back pain during baseball activities.

Last season, Miller stole 59 bases with an .825 OPS in 116 games between Double-A Reading and Triple-A Lehigh Valley.