For a second straight week, the Seahawks will likely be without one of their cornerstones along the offensive line and the backfield remains littered with injury-related questions heading into Sunday's rematch with the 49ers.

After sitting out Monday's 17-15 loss to Washington, guard Damien Lewis missed Thursday's practice with an elbow injury as well as a new non-injury medical designation. According to Gregg Bell of the Tacoma News Tribune, the second-year lineman had a cyst removed from his groin, setting him up to miss a second consecutive game and his third game total. He also sat out a Week 7 loss to New Orleans with a shoulder injury.

If Lewis isn't able to play as expected, Seattle will likely turn to reserve lineman Kyle Fuller, who made his first start at guard since 2018 on Monday. He struggled in pass protection, allowing six pressures and a pair of quarterback hits. Behind him, former fourth-round pick Phil Haynes could also be a replacement option under consideration after playing no offensive snaps in Week 12.

Meanwhile, after signing Adrian Peterson to their practice squad on Wednesday, it remains unclear who the Seahawks will have available at running back on Sunday. Starter Alex Collins, who has been nursing a groin injury for over a month, received a questionable designation on Friday. Travis Homer (calf) and Rashaad Penny (hamstring), who both were held out against Washington, returned to practice this week and also have been listed as questionable.

Even if Collins, Homer, and Penny all are deemed healthy enough to play against San Francisco, it's possible Seattle could elevate Peterson to the 53-man roster as insurance with all three backs at less than 100 percent. The 36-year old told reporters on Thursday that he would be ready to play if his number is called upon.

Aside from Peterson, the Seahawks could also elevate undrafted rookie Josh Johnson for a second straight game. The ex-Louisiana Monroe standout dressed and played on special teams, but did not receive any offensive snaps against Washington in his NFL debut.

The good news for Seattle is that besides Lewis' injury and the uncertainty in the backfield, the team looks to be fully healthy elsewhere. No other players received final injury designations, including guard Gabe Jackson and receiver DK Metcalf, who were both limited by knee and foot injuries in Thursday's practice.

As for the 49ers, who will arrive in the Pacific Northwest with a three-game winning streak, coach Kyle Shanahan's team will be without several key players. Most notably, standout receiver and do-it-all weapon Deebo Samuel and linebacker Dre Greenlaw have been ruled out with groin injuries. All-Pro linebacker Fred Warner also received a doubtful designation with a hamstring injury and is unlikely to suit up.

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