Despite dropping a 27-13 decision to the Cardinals on their home turf last Sunday, there’s been a positive vibe at the Seahawks practice facility this week.

Seattle energized its locker room and fan base by re-signing former All-Pro running back Marshawn Lynch as well as Robert Turbin to replace Chris Carson and C.J. Prosise, who suffered season-ending injuries against Arizona. Cornerback Shaquill Griffin returned to practice and defensive end Jadeveon Clowney also proclaimed there was “no way” he wouldn’t suit up against the 49ers in the season finale.

While those developments provide reason for optimism, there’s still a strong possibility the Seahawks will be without several key players in Sunday’s de facto NFC West title game, including Quandre Diggs. Missing the star free safety for a second straight week would be a major blow to the team's secondary in a crucial game.

Most concerningly for this week, Seattle's offensive line looks to be in shambles with just three days left until kickoff and it remains to be seen which five players will start against San Francisco.

Tackle Duane Brown underwent minor knee surgery on Monday and though coach Pete Carroll hinted there’s a chance he could return for the playoffs, he’s going to be sidelined as Russell Wilson’s blind side protector for at least one more week. Jamarco Jones struggled in his absence against Arizona, allowing Chandler Jones to record 4.0 sacks and six quarterback hits.

"It was hard," Carroll said reflecting on Jones' performance. "He went against a great guy and it worked him the whole day. He did a lot of things that were really good. The sacks that his guy had weren’t all on him."

Next to him, left guard Mike Iupati hasn’t practiced this week with a neck injury that caused him to miss a large chunk of last week’s defeat.

Compounding Seattle’s health issues in the trenches, center Joey Hunt has been battling a fibula injury for a couple of weeks, Jones and Germain Ifedi cropped up on Thursday’s practice report with shoulder and knee injuries respectively, and versatile reserve Ethan Pocic is nursing a core injury.

With right guard D.J. Fluker as the only exception, the Seahawks entire starting offensive line was either limited or did not participate in Thursday’s practice. Gearing up to play the NFL’s deepest, most talented defensive line, that’s anything but an ideal situation.

Entering the final week of the season, the 49ers rank fifth in the NFL in sacks (47), third in quarterback hurries (79), and fourth in the tackles for loss (85) per Pro Football Reference. Arik Armstead leads the team with 10.0 sacks, while first-round pick Nick Bosa has a great chance to hit double figure sacks in his rookie season feasting on Seattle’s line.

Assuming Jones will be able to play in Brown’s place for a second consecutive week, Seattle will have at least two reserve linemen in the starting lineup on Sunday. Iupati’s status remains up in the air, as Pocic would be his likely replacement if he’s unable to go.

In a worst-case scenario if Hunt wasn’t close to 100 percent, the Seahawks would have to roll out rookie Phil Haynes in his NFL debut in Iupati’s place alongside Pocic at center. Though the fourth-round pick out of Wake Forest has potential, he’s yet to play in an NFL game and asking him to play against the 49ers would likely be a recipe for disaster.

With one more practice remaining, there will be more clarity coming on Friday when Carroll speaks with the media and final injury reports are released. But with protecting Wilson imperative to Seattle’s chances on Sunday, missing two or more starters up front would be a gigantic obstacle for the team to overcome given the opponent.