Top prospect Aidan Miller is dealing with lower back soreness early in Spring Training, prompting the Philadelphia Phillies to take a cautious approach.

Miller has been held out of Grapefruit League action after reporting soreness one morning. Manager Rob Thomson said the issue does not appear to be serious and emphasized that the club is simply being careful this early in the spring. While Miller was hit by a pitch during batting practice last week, Thomson indicated that incident was not the cause of the current discomfort.

Veteran star Bryce Harper also referenced Miller’s health during a Spring Training broadcast, noting how important it is for the young infielder to stay healthy and continue his development. Harper’s comments suggested there’s no panic inside the clubhouse, just precaution.

At this point, Miller is considered day-to-day with no official timetable for a return. The Phillies appear focused on long-term health over short-term reps as one of their top prospects works through the minor setback.