Miller underwent core muscle surgery in October, Marc Topkin of the Tampa Bay Times reports.
Miller underwent the surgery multiple weeks ago but the specifics of the procedure weren't revealed until Thursday. The surgery was performed to address issues in Miller's groin and lower abdominals, two areas that caused the veteran infielder a lot of trouble during the regular season. The surgery carries with it a six-week rehab time, so Miller should be back to full health when spring training rolls around.
