HIIPA is just a thing teams say when they don't feel like keeping fans informed. Unless the player explicitly asks them not to share medical info it's pretty much part of being a pro athlete, including consenting to the team having complete access to your medical file.
He wasn't actually resting though, once they shut him down late last season he started rehab, and he was fully active in spring training. Until he wasn't. Clearly they think it was a mistake that he played through it last year, but they would surely have done scans by now (if not last fall) if necessary.
Perhaps more concerning, given we thought this was a guy the Phillies stole because of his wrist injury, is the back issues aren't new.
Back issues appeared on Miller’s draft medical reports, president of baseball operations Dave Dombrowski told The Athletic in March, but last year marked the first time they were “of any major consequence” for the 2023 first-rounder. Miller played through lower back pain for the last two months of 2025, stealing 22 bases across August and September despite his discomfort. He missed part of the final week of the Triple-A season and the Arizona Fall League to rehab.
When Miller arrived at spring training, he felt faster than last season. He said he was pain-free. He was hitting, fielding grounders, running the bases and more. Then, two weeks into spring training, the pain returned. He backed off activity and, at points during the spring, felt pain-free. But his baseball activity since then has been limited to occasionally playing catch and running through his ground-ball routine.