Miller tore his ACL during the Houston Texans' third preseason game last August and missed the entire 2019 campaign as a result.
The Patriots struggled to run the ball last season, ranking 25th in yards per carry and 18th in rushing offense. Adept as a receiver and pass-blocker, Miller could see significant playing time if Michel fails to improve on his disappointing 2019.
Miller joined Houston after spending the first four seasons of his career with the Miami Dolphins. In 2018, the 29-year-old's previous healthy campaign, he amassed 973 yards on the ground and five touchdowns.