It's no mystery how teams are approaching their matchups with the 49ers.

Time and time again, San Francisco's opponent has come out on its opening drive with the obvious intention of establishing the run.

We saw it in Week 6, when the Rams didn't attempt a pass on their opening drive, instead running it seven straight times for a touchdown.

We saw it in Week 7, when Washington ran the ball on its first 11 plays.

We saw it in Week 9, when the Cardinals gained 36 rushing yards on their first offensive play and finished their first drive with a 4-yard touchdown run.

And you can bet we'll see it again in Week 10, when the 49ers host the rival Seahawks on Monday night.

Last season, Seattle led the NFL in rushing with an average of 160.0 yards per game. The Seahawks haven't been as prolific this season, but their average of 131.7 rushing yards per contest still ranks seventh-best in the league. Quarterback Russell Wilson gets all the headlines -- and deservedly so with his 22:1 touchdown-to-interception ratio -- but it's the run game, led by Chris Carson, that opens up the play-action with which Wilson has been so effective.

NBC Sports Bay Area 49ers analyst Donte Whitner believes Carson, not Wilson, should be San Francisco's main concern Monday night.

"I'm more concerned with how the 49ers started the last two football games, with the teams coming out forcibly running the football, doing whatever they want to do, throwing them around, moving them around," Whitner said on Thursday's episode of "49ers Central." "This team, yeah, everyone is talking about Russell Wilson, Russell Wilson, but it's Chris Carson. He wants to run the football. The Seattle Seahawks want to run the football, and then throw the football second."

Carson is listed at 5-foot-11, 222 pounds, and isn't one to shy away from contact. Whitner, who spent 11 years in the NFL as a safety, knows firsthand that Carson isn't a fun running back to face from a defensive back's perspective.

"You have to stop the run, and you have to understand that the defensive backs in the NFL don't want to hit a guy like this," Whitner admitted. "They don't want to face a guy like this, because he's a physical specimen back there. He searches for contact."

Sound familiar? Carson reminds Whitner of a former bruising Seahawks running back: "He's similar to Marshawn Lynch in this offense."

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With linebacker Kwon Alexander out for the rest of the season with a torn pectoral, that thought should make the 49ers shudder, particularly given how their rush defense has performed as of late.

While a dominant pass rush has helped the 49ers establish the league's best passing defense, they're middle of the road (14th) in rush defense, and only one other NFL team has allowed more yards per rush than San Francisco (5.54) since Week 4.

Carson has fumbled four times this season and lost three, so he's not without his faults. But if the 49ers let him run wild Monday, it will be a long night for their defense.