Anthony Davis' on-again, off-again 49ers career took another strange turn Friday when he was ruled out of Sunday's game at Carolina because of a concussion.
Davis sustained the concussion at Thursday's practice and reported his symptoms afterward, according to a team spokesman. Davis was not listed on Thursday's participation report that immediately followed practice.
He has not renewed any discussion about retiring, the team said. Davis is now in the league's post-concussion protocol, and he was unavailable for comment. The 49ers did not have media access during Friday's walk-through prior to their afternoon departure to Charlotte.
John Theus, a rookie who did not suit up for Monday night's season opener, likely will be active as the 49ers' only backup tackle to starters Joe Staley and Trent Brown when they visit the Panthers.
Davis' comeback from a 2015 hiatus was cast in doubt last weekend, when he skipped Saturday's practice while pondering a return to retirement, multiple sources told this newspaper. Both Davis and coach Chip Kelly said "miscommunication" was to blame for last Saturday's situation.
Instead of starting at right guard as he had practiced the preceding two weeks, Davis was a backup at right tackle to Brown and played only the final three offensive snaps in Monday's 28-0 win over the Los Angeles Rams.
Davis started every game at right tackle for the 49ers his first five seasons after being a first-round draft pick out of Rutgers. Injuries in 2014, including a late-season concussion, led him to take off last season to recover physically. He participated in a sleep study at Stanford Medical Center this week, according to his social-media post on Snapchat.
