Sherman was released by the Seahawks on March 9 and was signed three days later by the 49ers, then claimed the Seahawks had lost their way. But his return to the stadium where he became a star is muddled by the fact that the 49ers (2-9) are out of the playoff race and struggling.
While the Seahawks (6-5) have won two in a row to remain in the hunt, the 49ers have lost two straight and are playing with a quarterback who began the season on the practice squad.
It remains to be seen how the Seattle crowd will react to Sherman.
"They'll be great," Seahawks head coach Pete Carroll said. "I mean, I think he's loved around here for all the great stuff that he did. I don't know that it's going to be noticeable what the reception is like. If it's noticeable then it's pretty significant. He did a lot of great stuff here. I don't think our fans think any differently than I do about that."
Seattle came from behind in the fourth quarter to beat the Carolina Panthers 30-27 last week, putting Seattle in the driver's seat for one of the two wild-card spots in the NFC. Holding tiebreakers over the Panthers and Cowboys, the Seahawks control their own destiny heading into the final month.
Quarterback Russell Wilson passed for 339 yards, two touchdowns and no interceptions in that game against Carolina, and the Seahawks had two players with more than 100 receiving yards -- Tyler Lockett (107) and David Moore (103).
Over the past nine games, Wilson has thrown 20 touchdown passes with just two interceptions.
The 49ers will again go with Nick Mullens at quarterback. He struggled in last week's 27-9 loss to Tampa Bay, throwing two interceptions and getting sacked four times.
"I know I said Nick didn't play very well," head coach Kyle Shanahan said of comments he made after the loss at Tampa Bay, "but no one played well and I didn't coach well. It was all of us. Nick did a good job in his first two games. (His play) was not the reason (the loss) happened, so that's not fair to do that to him."
Asked whether Mullens has locked down the starting job for the rest of the season, Shanahan said, "No. I feel the same way as I did after the Oakland game (a 34-3 win in Mullens' NFL debut). It's a week-to-week thing.
"Jimmy (Garoppolo) is our quarterback. Everyone knows that. C.J. (Beathard) got an opportunity when Jimmy got hurt, and Nick got an opportunity when C.J. got hurt. So we're playing this year out with our (Nos.) 2 and 3, and we'll see how games go.
"We're going to do everything we can to win a game. I know we're preparing with Nick, and if he ever struggles, I'd bring in C.J. We'll see how it goes."
To make matter worse for the 49ers' offense, they might be without wide receiver Marquise Goodwin, who is taking care of some personal issues. He leads the team in receiving touchdowns (four) and is tops among 49ers wideouts in receiving yards (339).
It leaves a lot to running back Matt Breida, who has had surprising success despite the team's struggles. The second-year back has rushed for 738 yards this season and ranks second among qualified rushers with 5.8 yards per carry.
"He's really fast and he likes to get on the edge. Our edge is definitely going to be tested," Seahawks linebacker Bobby Wagner said of Breida. "They're going to try to run outside. They have a lot of good runs to complement (and) have us thinking it's going to be an outside run and then it cuts back. It's definitely going to be a discipline game."
The 49ers have a pretty good defense, ranking 11th in the NFL in total defense and 10th against the run.
But the Seahawks lead the league in rushing, averaging 147.1 yards per game on the ground. None of Seattle's running backs is among the league leaders, but three of them -- Chris Carson, Mike Davis and Rashaad Penny -- have rushed for more than 300 yards apiece.
The Seahawks ran for just 75 yards against the Panthers, averaging a mere 2.7 yards per attempt.
"It's always important for us to run it and hopefully we can do a good job," Carroll stated. "If you look at their (49ers) stats, you'll see they're giving up a hundred yards a game rushing, which is really good and really solid. (San Francisco defensive coordinator Robert) Saleh is doing a good job with those guys on defense."
These two teams will face each other again just two weeks after Sunday's clash.