*Editor's note: Happy Thanksgiving. I hope everyone has a fantastic holiday with their friends, loved ones, and football. And food. Can never forget the food.* - Chris
That means Jonathan Martin will make his seventh start of the season at right tackle in Davis' place. Davis has been bitten badly by the injury bug all year, dealing with shoulder, knee, and ankle issues in addition to his concussion. Head coach Jim Harbaugh said Davis was still feel symptomatic this week and was not close to passing the league-imposed concussion protocol.
Quarterback Colin Kaepernick has been sacked an NFL-high 34 times, which has been a key factor in the team's offensive struggles. Martin has allowed a team-leading five sacks in 269 passing plays, according to Pro Football Focus. But the former Miami Dolphin has allowed pressures at a lower rate than Davis in 2014.
Davis has allowed 16 pressures, including three sacks, in 188 pass blocking plays - adding up to 8.51 percent of Kaepernick's drop backs. Martin's pressure rate is 8.18 percent.
But Davis has been the better run blocker, ranking 32nd in PFF's grades. Martin is 52nd.
The Seahawks' No. 1 defense has a pair of very good defensive ends in Michael Bennett and Cliff Avril who figure to rotate over Martin as Thursday's game goes on. Those two are fifth and sixth in PFF's pass rush rankings, despite both having four sacks, which ranks them outside the NFL's top 31 players. Seattle is allowing a league-leading 297 yards per game.
The 49ers will also be without tight end Derek Carrier, who sustained a foot injury in Sunday's win over Washington, leaving the 49ers with just one healthy tight end in Vernon Davis. Vance McDonald missed Sunday's game with a back injury, but practiced this week without a blue no-contact jersey. He is listed as questionable.
With Carrier out fullback Bruce Miller played 40 snaps, his third-highest total of the season. He also had three catches on three targets, both season highs.
Corner Tramaine Brock (hamstring) is listed as questionable, although it appears unlikely he will play. Nose tackle Glenn Dorsey has also been ruled out while he continues to come back from his torn biceps tendon. He did not practice this week.
Wideout/return man Bruce Ellington returned to practice this week after missing the team's last two games with an ankle injury. He is listed as questionable. With Perrish Cox returning punts against Washington, San Francisco started five drives inside their own 10-yard line.
49ers injury report
TE Derek Carrier (foot), T Anthony Davis (concussion), DT Glenn Dorsey (forearm)
CB Tramaine Brock (hamstring), WR Bruce Ellington (ankle), TE Vance McDonald (back)
Seahawks Injury Report
DE Demarcus Dobbs (knee), CB Jeremy Lane (glute)