In June, Mills was arrested and charged with second degree battery after allegedly punching a woman and knocking her unconscious in May.
Addressing Mills, Miles said Monday, "All I can tell you is we're going to handle it internally and work him right here."
"Those things take time and ... after an entire summer of suspension, we felt like, while this thing was still being decided, that we bring him onto the team and then continue that discipline," Miles said Monday evening, according to ESPN.com.
Former LSU running back Jeremy Hill, who pleaded guilty to a battery charge last summer, did not play the first five quarters of last season.
Mills is a two-year starter in LSU's defensive backfield, playing 25 of his first 26 games at cornerback. The 6-foot, 194-pound Mills is expected to move to play safety this season.
Mills was named a freshman All-American by multiple outlets in 2012 and recorded 67 tackles, four tackles for loss, three sacks and three interceptions over 13 games as a sophomore last season.
- Chris Johnson