The Seahawks head to Santa Clara this weekend to face the 49ers in their first NFC West game of the season, and both teams will be looking to bounce back from disappointing losses in Week 3. The Seahawks have had a lot of success against the 49ers in recent years, including at Levi's Stadium, but they also know they're facing a very tough challenge when they take on Kyle Shanahan's squad, which is 2-1 after losing to the Packers on a last-second field goal.

If the Seahawks are going to get back on track and avoid their first three-game losing streak in a decade, these are three key matchups that could make the difference in Sunday's game at Levi's Stadium:

1. Talented pass-catching duos vs. opposing secondaries.

The Seahawks feature in DK Metcalf and Tyler Lockett one of the best receiving duos in the NFL, while the 49ers counter with a formidable receiver/tight end duo of Deebo Samuel and George Kittle, and for both offenses, trying to get the ball in those players' hands will be key.

With Lockett and Metcalf, it has been a pick-your-poison situation for opposing defenses, with Lockett going for 278 yards and three scores in the first two games, then with Metcalf breaking out with 107 yards and a touchdown last week. The 49ers have a great defense, but they've had some issues on the back end, particularly with injuries at cornerback, and they also have been penalized for pass interference a league-high seven times. With San Francisco's depth being tested this weekend, the Seahawks will be looking for Lockett and Metcalf to take advantage.

On the other side of the ball, third-year receiver Deebo Samuel is off to a great start after missing much of last season due to injury. He currently ranks second in the league with 334 receiving yards on 20 catches, and he's going against a Seattle secondary that has struggled with some of the league's best receivers over the past two weeks.

And while he's not a receiver, tight end George Kittle is one of the biggest pass-catching threats in San Francisco's offense. The two-time Pro Bowler is a matchup nightmare for opposing defenses, and so far this season he has 15 catches for 187 yards, including seven for 92 last week. The Seahawks have done a pretty good job against him over the year—Kittle's high in receiving yards against Seattle is 86 yards, and he has not scored a touchdown in seven meetings—but that past success won't mean much if the defense doesn't take care of business against him Sunday.

"He's really become a special part of their team," Seahawks coach Pete Carroll said of Samuel. "I really see him as the star player for them. They utilize him in a fashion where they are always looking to get him the football, positioning him to make the plays, and counting on him to do the things that he's done well. They really have used him well in the sense that you can see what he has that's unique. He's really physical, he's fast enough to run away from guys, and he's got a great competitive streak about him. Between he and (George) Kittle, those two guys in getting them the ball, that's a lot of fire power in maybe a less traditional way than we would think. Those guys are all explosive and they make big things happen."

2. 49ers defensive ends Nick Bosa and Arik Armstead vs. Seattle's pass protection.

The Seahawks will be without starting right tackle Brandon Shell for the second week in a row, which only makes the challenge a little bigger when facing one of the NFL's best defensive fronts. The 49ers can throw a lot of different pass-rushers at an offense, and the two leading the way are Nick Bosa and Arik Armstead, one of the better defensive-end duos in the league.

Bosa was a Pro-Bowler as a rookie with 9 sacks and 16 TFLs, then missed almost all of last year with an injury. He's back and has a team-high 3.0 sacks to go along with 5 tackles for loss and 5 quarterback hits. But while Bosa has the stats and accolades, the Seahawks know they can't sleep on Armstead, who is quietly off to a great start as well. Armstead has only 1.0 sack and 4 tackles, but he's also the No. 10 ranked edge defender in the league according to Pro Football Focus, seven spots ahead of Bosa, and he's also San Francisco's highest-rated players on defense. His 16 QB Pressures, per PFF, are tied for fourth most in the NFL.

"Their defensive front is one of the best in the league," Seahawks quarterback Russell Wilson said. "They fly around, they are all over the place, and they have a lot of tremendous players. (Nick) Bosa, (Arik) Armstead, (D.J.) Jones, and all of the guys they have coming in the game. They are really talented. They have guys coming off of the bench in (Dee) Ford and other guys too. The biggest thing is their defensive line and what they do but (Fred) Warner is one of the best in the league, just on defense in general. They have really great safeties. They are a little banged up on the outside, but they have a really good scheme, they do a really good job of trying to get after it and how they do it, they are coached extremely well so we will have to bring our A game."

And while Shell is out again with an ankle injury, the Seahawks know they have one of the best in the business on the other side of the line, with Duane Brown playing as well as ever in his 14th season.

"He's so impressive, just what he's able to do," said offensive coordinator Shane Waldron. "Again, it's not a surprise when a couple of these guys I've seen from afar, and now being around them every day and seeing their daily approach, Duane's right there at the top of the ladder with that stuff. You see him, even in the times during training camp where he wasn't on the field every single day practicing, his work ethic in the weight room and his work ethic in the meetings and walkthroughs, everything was top notch. He's a guy that was able to seamlessly, without a ton of reps on the field, come out there and play at an extremely high level the past few weeks. He's accumulated so many reps of football throughout the course of his life that so much of it for him is the mental side, making sure he's staying sharp there. Then the physical side just takes over with his natural ability and how hard he's worked at it and just accumulated that foundation over the course of his career."

3. Which team fixes its issues with inconsistent play?

By now the Seahawks' first half vs. second-half disparities are well known, with the Seahawks scoring 62 first-half points through three games, and just 13 in the second half, including none in the third quarter. The defense, meanwhile, was strong through the first six quarters of the season, and has struggle to get stops ever since, starting with the Titans scoring 24 points in the second half and overtime to overcome a 15-point halftime deficit.

The 49ers, meanwhile, have recently had a problem with falling behind early then having to fight to get back into games. They fell behind 17-0 last week against Green Bay before coming back to take a late lead. The week before against the Eagles, the 49ers didn't score until the final seconds of the first half, then they used two more fourth-quarter scores take control of the game late.

While there are plenty of ways to win football games, including coming back from early deficits, or building big leads then hanging on, but whichever team can put together a more complete, four-quarter effort very well might have the edge in what figures to be a close game.