Niners right tackle Anthony Davis was still experiencing concussion symptoms Monday after he was injured in a win over the Giants on

Nov. 16, and his status for Thursday night’s game against Seattle is up in the air, head coach Jim Harbaugh said.

The 49ers are accustomed to playing without Davis this season. He has missed six games because of various injuries — he had hamstring and knee ailments earlier — after opening his career with 64 straight starts. On Sunday, Jonathan Martin made his sixth start of the season and allowed a sack and two quarterback hurries in a 17-13 win over Washington, according to Pro Football Focus.

The Seahawks are ranked 29th in the NFL in sacks and are on pace for 23. Last season, they ranked eighth in the league with 44 sacks.

Bowman update: Harbaugh said he doesn’t expect inside linebacker NaVorro Bowman to start practicing this week. Bowman, who tore two knee ligaments in the NFC Championship Game in January, became eligible to practice last Tuesday but has continued to rehab.

The 49ers have until Dec. 9 to decide whether to activate Bowman to the 53-man roster or end his season by keeping him on the physically unable to perform list. Harbaugh and defensive coordinator Vic Fangio have acknowledged that Bowman might not play in 2014.

“Obviously, we want to have him back on the field,” quarterback Colin Kaepernick said. “It has to be when he’s ready, when he’s healthy. You don’t want to have him go out too soon and reinjure something.”

Injured TEs: Tight end Derek Carrier, who returned to Sunday’s game after suffering a foot injury, was sporting a walking boot on his right foot in the locker room. Carrier served as the No. 2 tight end against Washington because Vance McDonald was inactive because of a hip injury he apparently suffered in practice last week.

Ben Margot / Associated Press

Harbaugh said it was possible the 49ers would activate Garrett Celek, who has been on the PUP list this season with a back injury and returned to practice last week.