At this time last week, the Seattle Seahawks were alone atop the NFC West at 4-3.

But by Sunday night, they could find themselves in last place. A loss to the Los Angeles Rams at Lumen Field would assure as much regardless of whether the Arizona Cardinals win or lose on the road against the Chicago Bears.

Such is life in the NFL's tightest division.

Entering Week 9, the Cardinals, San Francisco 49ers and Seahawks are all tied at 4-4, and the Rams are just half a game behind at 3-4. Arizona holds the tiebreaker by virtue of its 2-0 start in NFC West play. The Rams-Seahawks game on Sunday (4:25 p.m. ET, Fox) is the first of eight NFC West matchups to close the season.

Elsewhere in the NFC, the gap between first and last place is 3 games in the East, two in the North and four in the South. The top and bottom spots in all four AFC divisions are separated by 3 to 5 games.

Why is the NFC West closer than the others? Among the reasons, the 49ers -- a Super Bowl favorite to start the season -- have been plagued by injuries, and the Cardinals have kicked three game-winning field goals.

Here's a breakdown of where things stand with the Seahawks, 49ers, Rams and Cardinals, plus how the NFC West might be won. -- Brady Henderson

Arizona Cardinals (4-4)

FPI's overall ranking: No. 21
Chances to win division: 32.9%
Chances to make the playoffs: 38.2%
Next five games: vs. Chicago Bears, vs. New York Jets, BYE, at Seattle, at Minnesota Vikings

Assess the quarterback: Kyler Murray is playing some of the best football of his career -- ranking third in the NFL in QBR (74.4) -- thanks to an intimate understanding of the Cardinals' scheme, a clean bill of health and both a comfortability and happiness with the coaches and players around him. Now in Year 6, he has faced a majority of what defenses are throwing at him.

Cardinals' X factor: WR Marvin Harrison Jr. When the fourth overall pick gets going, he -- as the kids say -- eats. Harrison, who had 26 catches for 411 yards and five touchdowns, has the capability to make any touch into a scoring play and change the direction of a game. His third-quarter touchdown against the Dolphins in Week 8 catalyzed Arizona's final two scoring drives in the victory. When he can string together a series of catches, it opens up the offense for everyone else.

Biggest concern going forward: Consistency. The Cardinals have found a bit of a rhythm with back-to-back wins for the first time since 2021. Arizona needs to fix some persistent issues -- for example, improving their third-down defense, which ranks last in the NFL -- or it will be at risk of getting passed in the division.

Reason for optimism: When the Cardinals' offense is clicking, it's as good as any offense in the NFL. It can deploy a mix of run -- between James Conner and Murray -- and pass that keeps a defense on its toes because of the unknown, namely whether Murray will run or throw. Arizona has shown the ability to score points quickly or eat the clock with an offense that can do it all from every angle.

Biggest divisional game left on schedule: There are really two. The first is Week 12 at Seattle because that's the next one and with the division so close right now, that game can add some separation in the tiebreakers with wins over all three of their NFC West rivals. But the most important one very well might end up being the last game of the season, when the 49ers visit the Cardinals. The division could come down to that.

Key player expected back from injury: Rookie defensive lineman Darius Robinson. The second of Arizona's two first-round picks is expected back in the next week or two from a calf injury that has sidelined him this season. His presence will give the Cardinals an instant boost on a defensive front that has been hampered by injuries, especially at edge rush, which is down two of its top three options. -- Josh Weinfuss

Los Angeles Rams (3-4)

FPI's overall ranking: No. 18
Chances to win division: 15.5%
Chances to make the playoffs: 19.5%
Next five games: at Seattle, vs. Miami Dolphins, at New England Patriots, vs. Philadelphia Eagles, at New Orleans Saints

Assess the quarterback: The Rams feel great about quarterback Matthew Stafford, who had his best game of the season Thursday night when he had both Cooper Kupp and Puka Nacua for an entire game. In that game, he threw more touchdown passes (four) than he had in the first six games of the season (three).

Rams' X factor: Nacua. There's no doubt the Rams missed Nacua for the five-plus games he was on IR because of a right knee injury. The receiver had his eighth game with 100 receiving yards Thursday in his 19th career game, according to ESPN Research. And he did that despite catching just a few from Stafford leading up to the game because of the short week.

Biggest concern going forward: The secondary. The Rams have seen improvement in this area this season, especially since the return of cornerback Darious Williams, but it might be the weakest position group on the field. Los Angeles has a young defense and hasn't had an elite player in the secondary since trading Jalen Ramsey in March 2023.

Reason for optimism: Week 8 win against the Minnesota Vikings. The Rams got a glimpse of what they hoped this offense would look like before they were hit by injuries, scoring a season-high 30 points against a team ranked first in defensive DVOA. Los Angeles had a slow start to the season but is healthy in time to be in the playoff conversation.

Biggest divisional game left on schedule: Week 17 vs. Cardinals. There's no bad pick of the remaining four divisional games, but beating Arizona is important because they've already lost to them this season. Arizona beat Los Angeles 41-10 in Week 3, a game in which Stafford took nine hits and five sacks, and Kyren Williams was held to 25 yards on 12 carries.

Key player expected back from injury: OL Steve Avila. The Rams have been hit hard on the offensive line, including Avila, who is on IR because of an MCL sprain. When Avila and Jonah Jackson return, the Rams should have the majority of their preferred starting offense back. The line has looked better of late, but there's no doubt Avila's and Jackson's return will be a boost. -- Sarah Barshop

San Francisco 49ers (4-4)

FPI's overall ranking: No. 6
Chances to win division: 37.8%
Chances to make the playoffs: 44.2%
Next five games: BYE, at Tampa Bay Buccaneers, vs. Seattle, at Green Bay Packers, at Buffalo Bills

Assess the quarterback: For the most part, Brock Purdy has played well this season, but a rash of injuries at the skill positions combined with changing defensive game plans has made life more difficult for the offense. It has led to Purdy holding on to the ball longer, being forced to scramble more often and a decrease in yards after the catch. Purdy is still rolling toward a massive contract extension in the offseason, though the price tag might depend on how he closes out the year.

49ers' X factor: LB Dre Greenlaw. Aside from the Herculean efforts of Fred Warner, the Niners have simply not been good enough at linebacker. Greenlaw is working his way back from a torn Achilles and it seems unlikely he'll be at full strength this season. But San Francisco hopes he can return in the coming weeks and be an upgrade over the others who have filled in for him. Even at 80-85%, Greenlaw would help this defense significantly.

Biggest concern going forward: Special teams. In four losses, the 49ers have been outscored by an average of five points per game and three of those defeats have been by six points or fewer. The margin for error is slimmer for this team than it has been in the past, which is why a big special teams play or two can mean the difference between winning and losing. Through Week 8, San Francisco ranks 31st in the NFL in special teams expected points added (minus-17.89).

Reason for optimism: It's obviously not the preferred method of getting to the postseason, but this isn't the first time the Niners have started slow and gone on a run. Since Kyle Shanahan took over in 2017, the 49ers are a combined 39-22 in November, December and January, a 63.9% win percentage that ranks third in the NFL in that span. Most recently, they stormed back from a 3-5 start in 2021 to finish 10-7 and a 3-4 start that ended in a 13-4 record in 2022. Both teams made the NFC Championship Game. It also doesn't hurt that the NFC West is wide open.

Biggest divisional game left on schedule: Week 17 at Arizona. Because the 49ers blew double-digit leads against the Rams and Cardinals, every divisional game the rest of the way carries more weight than usual. But we'll opt for the season-ender in the desert based on the premise that this division is so up in the air that it very well could come down to the last week. The 49ers also surely wouldn't mind a measure of revenge for the walk-off loss to Arizona in Week 5.

Key player expected back from injury: RB Christian McCaffrey. Candidly, the 49ers' season might depend on not only McCaffrey's return but also his ability to be at or near his usual, prodigious levels of productivity. They are aiming for a Nov. 10 return against Tampa Bay. If that happens, the offense has a chance to take off and carry this team to contention. -- Nick Wagoner

Seattle Seahawks (4-4)

FPI's overall ranking: No. 24
Chances to win division: 13.8%
Chances to make the playoffs: 17.7%
Next five games: vs. Rams, BYE, at San Francisco, vs. Arizona, at Jets

Assess the quarterback: Geno Smith has been solid, but the Seahawks have needed him to be spectacular given all of their shortcomings. Often chasing big deficits and having no run game to lean on, Smith (14th in QBR) leads the NFL in attempts (308) and yards (2,197) but has eight TD passes compared to seven interceptions, with tough luck involved in a few of the picks.

Seahawks' X factor: Kenneth Walker III. The Seahawks' RB1 is tied for fourth with seven touchdowns from scrimmage even though he sat out two games. Walker is a difference-maker, but the Seahawks haven't involved him enough. They're last in the NFL in designed rush rate in part because they've abandoned the run in several games while playing from behind.

Biggest concern going forward: The run defense is a mess. The Seahawks are giving up the fourth-most rushing yards per game (148.4) and the fifth-highest yards-per-carry average (4.9). It has remained a weakness even as Seattle's defense has improved its health up front. Coach Mike Macdonald has identified it as a second-level issue, which helps explain why they traded for linebacker Ernest Jones IV.

Reason for optimism: Jones, acquired from the Tennessee Titans for Jerome Baker and a fourth-round pick, should help Seattle's run defense. He's known as a strong run defender and plays with an aggressive, downhill style that the Seahawks weren't getting from Baker. Their run defense wasn't much better in Jones' debut, though he had 15 tackles after practicing with his new team twice.

Biggest divisional game left on schedule: Week 11 at 49ers. All of the games look big given the tightly packed standings, but none are bigger than the rematch with the 49ers. San Francisco won the first meeting at Lumen Field, so losing both would give the 49ers the head-to-head tiebreaker. The Seahawks will be coming off their bye, which should help as they try to end a six-game losing streak to their division rivals.

Key player expected back from injury: Abraham Lucas' long-awaited return appears to be getting closer. The third-year right tackle -- arguably the team's top O-lineman as a rookie in 2022 -- has been on the physically unable to perform list while working his way back from surgery for a knee issue that sidelined him for much of 2023. He's back at practice and could be on the field in Week 11. -- Henderson