Joe Staley expects to play Sunday

SANTA CLARA, Calif. -- As the San Francisco 49ers concluded their practice for Sunday's big home game against NFC West rival Seattle, it appears they will have one key member of the left side of their offensive line.

Star left tackle Joe Staley practiced Friday for the second straight day after suffering a knee injury in the first quarter against St. Louis that kept him out for the rest of the game. Initially, he was expected to miss a couple of games. He said Friday he expects to play against the Seahawks. Officially, he is listed as questionable.

Standout left guard Mike Iupati is also listed as questionable, but he seems like more of a longshot than Staley. Iupati didn't practice all week. He has missed the past two games with a sprained knee. Adam Snyder will play at left guard if Iupati can't go.

The impact of Staley being on pace to play is big. It means right guard Alex Boone will stay in place. He moved to left tackle when Staley was hurt. The inexperienced Joe Looney was inserted at Boone's spot. The makeshift line played well against the Rams, but the 49ers were dealing with downgrades at three positions because of the injuries.

The unit has been struggling overall, allowing half of its 30 sacks in the past four weeks. It also struggled against the Seahawks in a 29-3 Week 2 loss at Seattle. According to ESPN Stats & Information, the Seahawks put 49ers' quarterback Colin Kaepernick under duress a season-high 37 percent of his drop backs.

Staley and Iupati are vital to the 49ers' ground game, as well. According to ESPN Stats & Information, the 49ers have 1,517 rushing yards to the left side, fourth most in the NFL. So, even if it's just Staley who is back Sunday, it will be beneficial to the 49ers.