SANTA CLARA – Defensive lineman Justin Smith, whose non-practice days this season have not been injury-related, is experiencing an undisclosed back issue, the 49ers revealed on their practice participation report Monday evening.
The 49ers held a walk-through practice on Monday, but they were required to disclose a participation report as if the team had a full practice. The 49ers play the Seattle Seahawks on Thursday night at Levi’s Stadium.
Smith, a 14-year veteran, has routinely gotten rest days on Wednesdays and Thursdays. This is the first time Smith has appeared on the participation report this season with an injury.
Smith’s sack and forced fumble on the 49ers’ final defensive play of the game helped preserve a 17-13 victory over Washington on Sunday.
Tackle Anthony Davis was still experiencing concussion symptoms on Monday, coach Jim Harbaugh said. He remains questionable for Thursday’s game after sustaining a concussion Nov. 16 against the New York Giants.
Cornerback Tramaine Brock (hamstring), tight end Derek Carrier (foot), nose tackle Glenn Dorsey (forearm) and rookie receiver/return man Bruce Ellington would not have practiced, either.
Harbaugh said the 49ers could promoted tight end Garrett Celek to the 53-man roster for Thursday’s game. Backup Vance McDonald did not play Sunday due to a back injury, but he would have been able to take part in limited practice on Monday.
The 49ers are scheduled to hold their first full practice during the regular season inside Levi’s Stadium on Tuesday afternoon.
49ERS
Did not participate
CB Tramaine Brock (hamstring)
TE Derek Carrier (foot)
T Anthony Davis (concussion)
DT Glenn Dorsey (forearm)
WR Bruce Ellington (ankle)
DE Justin Smith (back)
Limited participation
RB Frank Gore (knee)
TE Vance McDonald (back)
Full participation
WR Brandon Lloyd (quadricep)
RB Bruce Miller (shoulder)
S Eric Reid (ankle)
S Raymond Ventrone (groin)
SEAHAWKS
Did not participate
TE Cooper Helfet (ankle)
C Max Unger (knee/ankle)
LB Kevin Pierre-Louis (shoilder)
Limited participation
WR Jermaine Kearse (ankle)
RB Marshawn Lynch (back)
G James Carpenter (ankle)
DE Demarcus Dobbs (knee)
CB Marcus Burley (hamstring)
CB Jeremy Lane (glute)
