The NFL season has officially entered its second month, and some of the leading teams have begun to hit their stride while others still find themselves in desperate need of some positive developments and consistency.

Two teams remain unbeaten and lay perfect records on the line this week. The 4-0 Philadelphia Eagles welcome in the Denver Broncos, and the 4-0 Buffalo Bills host the New England Patriots on Sunday night.

Meanwhile, the Tennessee Titans, New York Jets and New Orleans Saints all look to snap four-game losing streaks and earn their first wins of the year.

This week’s action kicked off Thursday night with a meeting of NFC West rivals as the Los Angeles Rams hosted the San Francisco 49ers. A London-based contest kicks off the action on Sunday as the Minnesota Vikings and Cleveland Browns face each other, and the Kansas City Chiefs and Jacksonville Jaguars wrap up the action on Monday night.

Here are five of the leading storylines to follow this week.

Now or never?

The Baltimore Ravens return to M&T Bank Stadium in an even more desperate position than they found themselves in last week when they faced off with the Chiefs, who, like the Ravens, badly needed a victory to help rebound from a slow start to the season.

The Ravens instead delivered their worst performance of the season, fell to 1-3 and left Arrowhead Stadium with an even more expansive injury list, which included quarterback Lamar Jackson (hamstring), leading tackler Roquan Smith (hamstring), and top cornerbacks Marlon Humphrey (calf) and Nate Wiggins (elbow). Then on Monday, the Ravens learned that they’ll be without their best interior defensive lineman, as Nnamdi Madubuike’s neck injury, which had landed him on injured reserve, turned out to be season-ending.

The Ravens badly need to snap this two-game slide. Since 1970, only 16 NFL teams have managed to reach the playoffs after starting the year 1-4 or worse. And only four have done so after starting 1-5 or worse. The Ravens this week face a hungry Houston Texans team that also started slow before showing signs of improvement and earning its first victory last week. Now the Texans aim to build on that win and start chasing AFC South rivals Indianapolis and Jacksonville, who own 3-1 records.

Cooper Rush will start in place of Jackson, and the former Dallas Cowboys quarterback has had some bright moments in previous years. But he struggled in relief of Jackson against Kansas City. This could call for a strong dose of Derrick Henry; however, the Ravens haven’t gotten great production from him in recent weeks. Henry, who ranked second in rushing yards last season and gashed Buffalo for 169 yards and two touchdowns on 18 carries in the opener, has averaged just 38 rushing yards in his last three outings while carrying the ball just 10 times per game.

Houston has allowed 4.2 rushing yards per attempt (15th), so perhaps Henry can get back on track this week. The Ravens certainly need a spark from somewhere if they hope to catch up to the AFC North-leading Pittsburgh Steelers (3-1 and on a bye) and Cincinnati Bengals (2-2, facing a tall task against Detroit). (Texans at Ravens, 1 p.m. ET, Sunday, CBS)

Dillon Gabriel’s debut

A week after the New York Giants turned to rookie Jaxson Dart at quarterback, the Cleveland Browns have also made a change at quarterback, giving third-round pick Dillon Gabriel the nod over the ineffective Joe Flacco. The move makes Gabriel the third rookie quarterback to start for his team this season (joining Dart and Tennessee’s Cam Ward) and the 41st quarterback to start for the Browns since 1999.

Gabriel, who in college spent time at Central Florida, Oklahoma and Oregon, showed promise in the preseason, completing 67.6 percent of his passes (25-for-37) for 272 yards, a touchdown and an interception. Cleveland coaches are hoping that he can help spark an offense that has averaged only 14 points per game.

Gabriel will make his debut across the pond as the Browns face the Vikings on Sunday morning in London. He faces a stiff test against a Vikings defense that ranks third against the pass (only 151.1 yards per game). Ball security has been an issue for the Browns, who have turned it over a league-leading eight times (six interceptions, two fumbles). Meanwhile, the Vikings have forced seven turnovers (two interceptions, five fumbles), which is tied for fourth most in the NFL.

The Vikings will start Carson Wentz in place of the injured J.J. McCarthy for a third straight game and aim to rebound from a loss to Pittsburgh in Ireland last week. (Vikings vs. Browns in London, 9:30 a.m. ET, Sunday, NFLN)

A.J. Brown’s plight

It’s been a frustrating first month of the season for the Pro Bowl wide receiver. Aside from the six-catch, 109-yard day in Week 3 against the Rams, Brown has found opportunities hard to come by, averaging 2.6 catches for 14 yards on six targets per game. Yet, the Eagles are 4-0, and coach Nick Sirianni really doesn’t care about style points.

After last week’s game (two catches for 7 yards), Brown made a cryptic social media post about how to handle a situation where one feels unwanted. A couple of days later, Brown explained, “I let my frustrations boil over.’”He further explained that he just wants to help the Eagles win, and Sirianni swears the Eagles still view Brown as a vital piece of the puzzle.

This week, the Eagles look to extend their win streak to five games when they face the Broncos. Will Sirianni dial up a steady dose of Brown to appease the receiver? The Broncos boast a stingy defense, particularly against the run, holding teams to just 99.3 yards per game. So, the Eagles could look to air it out on Sunday. But Denver also has a talented shutdown cornerback in Patrick Surtain II, so Brown is gearing up for a challenging matchup. But he would have it no other way.

Will the wide receiver finally regain the level of involvement that he craves? And more importantly, will the Eagles — who this season have won in just about every way possible — get the job again and give Sirianni his third 5-0 start since 2022? (Broncos at Eagles, 1 p.m. ET Sunday, CBS).

A.J. Brown was largely uninvolved in the Eagles’ latest win. But with Philly at 4-0, how upset can he be? (Denny Medley / Imagn Images)

Reborn QBs reunion

Back in 2018, the Browns made Baker Mayfield the first pick of the draft. Two picks later, the Jets selected Sam Darnold. But after three turnover-filled seasons, the Jets shipped Darnold to the Carolina Panthers, and he started 11 of 12 games that 2021 season.

The following offseason, Mayfield also found himself on the move to the Panthers, as the Browns sent him to Carolina, where he backed up Darnold for six games and then made six starts himself before getting released and picked up by the Rams.

The five-game stint with the Rams helped provide Mayfield the career reset he needed, and in the offseason of 2023, he signed with the Tampa Bay Buccaneers, where he has flourished while finding a long-term home. That same offseason, Darnold signed with the 49ers, where, despite serving as a backup, he too received the reset he needed before he signed with the Vikings in 2024. Mayfield and Darnold each earned Pro Bowl honors after strong 2024 campaigns.

Now, the survivors of dysfunctional franchises meet again as opponents in Seattle, where Mayfield and the Buccaneers visit Darnold’s Seattle Seahawks. Both leaders of teams that sport 3-1 records, Darnold and Mayfield have also put up similar numbers. Darnold has passed for 905 yards, five touchdowns and two interceptions, and Mayfield has passed for 904 yards, eight touchdowns and one interception. Darnold has directed game-winning drives in two of Seattle’s three wins, and Mayfield directed game-winning drives in three straight Tampa Bay wins before last week’s loss to Philadelphia.

Which of these gunslingers leads his team to victory on Sunday? Mayfield, whose Buccaneers have displayed great resilience while overcoming an early wave of injuries and are looking to rebound from last week’s loss to the Eagles? Or Darnold, whose Seahawks rebounded from a season-opening loss to the 49ers to win three straight? (Buccaneers at Seahawks, 4:05 p.m. Sunday, CBS).

Momentum swing for Kansas City?

After weeks of disjointed showings, the Chiefs finally looked a lot like their old selves last week against the Ravens. The return of speedy receiver Xavier Worthy helped reignite a sputtering offense on multiple fronts, and Kansas City exceeded its scoring average for the season by 17 points.

Now the Chiefs will try to extend their win streak to three games and also reel in the Los Angeles Chargers, who lead the AFC West with a 3-1 record. To do so, Patrick Mahomes and company will have to deliver another effective performance and ensure ball security remains a priority as they face the Jaguars, who boast a ball-hawking defense that has recorded at least three takeaways in each of its four contests this season.

With Worthy back on the field for the first time since his Week 1 injury in a collision with Travis Kelce, the Chiefs regained a big-play threat last week. The second-year pro made five catches for 83 yards and also ripped off a 35-yard run. He also helped open up things underneath for fellow pass catchers Kelce (five catches for 48 yards), JuJu Smith-Schuster (four catches for 36 yards and a touchdown) and Hollywood Brown (three catches for 38 yards and a touchdown. The Chiefs’ offense had its most productive day in terms of points, yards and first downs, and Mahomes posted his best passer rating (124.8) of the season and didn’t turn the ball over for the first time since Week 1.

The Jaguars also enter this game on a two-game win streak after beating the Texans in Week 3 and the 49ers in Week 4. This will serve as a good measuring stick game for Liam Coen’s young team, and also help them keep pace with the Indianapolis Colts (also 3-1 in the AFC South), who host the Las Vegas Raiders this week. (Chiefs at Jaguars, 8:15 p.m. ET, Monday, ESPN)

(Top photo of Travis Kelce, JuJu Smith-Schuster and Patrick Mahomes: Denny Medley / Imagn Images)