Phillies manager Rob Thomson said Tuesday that Miller (back) has increased his rehab activities but is not yet swinging a bat, Todd Zolecki of MLB.com reports.
The nagging back injury has been bothering Miller going back to the fall, and his baseball activity is apparently still pretty limited as he's opened the campaign on Triple-A Lehigh Valley's injured list. Once cleared for all activities, the 21-year-old top prospect will need some time to build up to game readiness after missing all of spring training.