He joined fellow running back Sony Michel on the PUP (physically unable to perform) list, so he won’t practice immediately. Both backs can come off the list at any time, but they’re nursing injuries.
Miller and Michel are on the PUP/active list, which is different than the PUP/reserve list. The PUP/active list means a player can return at any time, but they take up a roster spot. The PUP/reserve list leaves an open roster spot, but the player must sit out the first six weeks of the season.
Miller missed the 2019 season with an ACL injury and a few other minor injuries. He’s joining a backfield that includes Michel, James White, Rex Burkhead and Damien Harris. Michel will likely join the PUP/reserve list — giving Miller an early opportunity to take over as the lead back.