SANTA CLARA – After playing in his first loss in over a year, Nick Bosa felt like most 49ers’ fans last Sunday night.
“I was pretty annoyed,” Bosa said. “At night, I called my loved ones and tried to get my mind off it that night.”
The last-second loss to the Green Bay Packers was a wake-up call for the previously unbeaten 49ers. Then came Monday, and a message was made loud and clear how the 49ers must reverse course Sunday when they host the rival Seattle Seahawks.
“The next day, we had a pretty, uh, I don’t know what to call it, but we had some interesting meetings, that we had to own up to it,” Bosa added. “A lot of us didn’t do the job we definitely could have done.”
Next on their to-do list is to hold serve in the vicious NFC West.
They must hand Russell Wilson the first three-game losing streak of his 10-year career as the Seahawks’ quarterback/escape artist.
And they must make sure Jimmy Garoppolo does not lose back-to-back starts for the first time in his career (28-10 all-time as a starter).
Here are five ways for the 49ers to pull that off:

1. READY, SET, GO!
Enough of these slow starts by the 49ers’ offense. It put them in a 17-0 hole last game, and it had them go 3-and-out on their first three series in Week 2 at Philadelphia.
If Kyle Shanahan still scripts a 24-play opening menu, it’s time to dial up early magic.
“He has his own process, and you don’t want to mess with that too much,” Garoppolo warned. “He’s had success with it in the past, so he kind of handles the openers.”
Shanahan never calls plays Nos. 1-24 in the order planned, of course. Defensive formations and personnel groups alter things. It seems the 49ers have been caught off guard these opening games, more so than they’re setting up opponents for second-half wizardry.
Of their seven drives in the first quarter this season, the 49ers have produced just one touchdown (Trey Lance pass to Trent Sherfield, at Detroit) and only 98 net yards (31st in NFL). Garoppolo’s first-quarter passer rating: 67.5 (101.2 overall; 136.0 on third downs). A nice start could help the 49ers from late-game theatrics like so many recent games with Seattle.

2. DEFENDING DEEP BALL
Wilson arguably throws the best deep ball in the NFL. He has exceptional targets in Tyler Lockett and D.K. Metcalf, although Lockett (hip) missed Thursday’s practice and Metcalf (foot) was limited.
What do the 49ers have? Trouble.
The 49ers have been penalized a NFL-high seven times for defensive pass interference (two on Deommodore Lenoir, two on Josh Norman, one apiece on Emmanuel Moseley, Fred Warner and Dontae Johnson).
“Guys have got to be confident when the ball is in the air,” defensive coordinator DeMeco Ryans said. “Guys are tight in coverage. … Guys have to be cleaner at the catch point.”
Of Wilson’s seven touchdown passes, three have come over 60 yards, including scores by Lockett in each of their first two games.
Three P.I. calls resulted in third-down conversions Sunday night in the Packers’ win over the 49ers. Josh Norman’s lung injury could prompt the 49ers to debut Dre Kirkpatrick, who’s faced Wilson four times in his career.
This will be the first time Lenoir encounters Mr. Unlimited (Wilson’s self-dubbed alter ego), as might be the case if the 49ers activate fellow rookie Ambry Thomas for the first time since the season opener.

3. RUSHING REBIRTH
Seattle will load box. Safety Jamal Adams will line up anywhere and star linebacker Bobby Wagner is forever lurking to make plays. The Seahawks haven’t made enough plays against the run, however.
They’re allowing 155 rushing yards per game (third-worst in the NFL). OK, but the 49ers must prove they have a running back capable of following blockers, and Trey Sermon didn’t seem too confident doing that in his first career start last game (10 carries, 31 yards).
“There were definite things he improved on as the game wore on,” offensive coordinator Mike McDaniel said. “Also, he’d been shortchanged, in terms of: he hasn’t played tackle football that much, when you really think about it.”
Fact check: Sermon had 455 carries and 48 receptions in four years of college football at Oklahoma and Ohio State, plus 16 carries in the 49ers’ preseason. Sermon got concussed on his first carry two weeks ago at Philly.
McDaniel noted that Sermon’s practice habits this week earned his teammates’ trust. Still, Elijah Mitchell (shoulder) could have a say if he returns, and perhaps it’s time to see Trenton Cannon race to the boundary in the outside-zone scheme.

4. KNOW EMERGENCY EXITS
Before each game, defensive line coach Kris Kocurek compiles video clips of where quarterbacks’ preferred escape routes. Wilson has made a living off those, or at least in terms of moving from the pocket to buy time and throw on the run.
“Just knowing where he likes to escape each way, and knowing he’s going to hold onto it,” Bosa said. “You have to keep going in your rush, even if you think you’re blocked, you have to keep going, but not get too out of your rush, either, to where you’re letting him find the escape route he wants.”
Arik Armstead had the 49ers’ only sack on a quick-throwing Aaron Rodgers last game. Wilson will provide more opportunities for sacks (eight this year).
Because Bosa is drawing so many double-team blocks and more attention than his 2019 rookie dominance, he noted that the 49ers must deploy countermeasures.
That includes stunts, twists and “certain chip eaters that Kris has used over the years,” Bosa said. “We’ve just got to get them called, execute them and I need to be better off of the chip, and not just stand there shocked like it’s happening.”
Bosa “definitely knows” he didn’t sack Wilson in either of their 2019 meetings, “but I’d like to get him, for sure.”

5. COACH ‘EM UP
After scoring a franchise-record 459 points last season, the Seahawks’ offensive scheme has changed a bit with new coordinator Shane Waldron. He previously was with the Los Angeles Rams and thus brought with him some concepts that mirror the 49ers’ scheme.
Former 49ers linebacker Ken Norton Jr. is in his fourth season as the defensive coordinator, and that unit is still where Pete Carroll makes his mark. Carroll, by the way, has more wins over the 49ers (regular season and playoffs) than any other coach, one ahead of Paul Brown and Don Shula, according to The Associated Press’ Josh Dubow.
Shanahan, meanwhile, came under fire last game for debatable clock management and a fourth-and-1 punt call, so a bounce-back performance would do him good. Shanahan is 10-14 in NFC West action since 2017, and 29-35 overall in regular-season action.
“This adds a lot of fuel. It’s a division game, the ones we have to win now,” defensive tackle D.J. Jones said, “so we aren’t scrapping at the end of the season.”