Anthony Davis has retired again from the NFL.
Davis sat out last year in part because of concerns over a concussion before deciding to return to the Niners this summer. He suffered another concussion in practice on Sept. 15 and has not played since.
Davis was slated to start at right guard, but missed the final practice before the season opener for non-injury reasons.
Davis was one of the NFL's best right tackles during the 49ers' run of three straight NFC Championship Games.