You're only as good as your weakest link, and that's particularly true in the NFL. Now that the 2020 season is underway, these are the biggest headaches for each team.
Arizona's secondary was consistently gashed last season, allowing the second most passing yards per game. The team is hopeful that Patrick Peterson can have a rebound campaign, but that might not be enough to keep them in the game consistently with concerns at other spots.
With the addition of first-round pick A.J. Terrell, Atlanta hoped their secondary issues were finally fixed. That wasn't apparent in Week 1, when Russell Wilson threw for 322 yards and four touchdowns. Head coach Dan Quinn is running out of time to fix the issues.
Baltimore has more talent at linebacker this year after selecting Patrick Queen in the first round, and he had a terrific debut with eight tackles and a sack. That's reason to be optimistic the team found it's answer after losing C.J. Mosley two years ago, but he should still be expected to make rookie mistakes.
Buffalo has a nearly complete team after adding Stefon Diggs in the offseason. Still, there are concerns about Josh Allen's accuracy issues, which were on full display in Week 1 with some bad throws to wide open receivers. Allen has yet to complete 60 percent of his passes in a season, and the Bills desperately need more stability to compete with the elite teams in the league.
The Panthers defense is a work in progress, losing several key players from last year's roster and spending their entire draft on that side of the ball. The Raiders put up 34 points on the Panthers in Week 1, while Carolina failed to record a sack or turnover. The offense has talent, but it will be difficult for them to score enough points with the way the defense has looked so far.
Mitchell Trubisky beat out Nick Foles for the starting quarterback job in training camp, but he struggled with his accuracy for the first three quarters at Detroit in Week 1. He was able to help orchestrate a comeback against Detroit's banged up secondary late in the game, but many of the accuracy issues that have plagued Trubisky so far in his career returned.
The Bengals drafted three linebackers this year, so some growing pains should certainly be expected. The team allowed yards rushing to the Chargers in Week 1, showing a work in progress for the group with Josh Bynes and Germaine Pratt the "veterans" setting an example for the youngsters.
Baker Mayfield had a terribly disappointing sophomore year in 2019, and he wasn't much better in Week 1 vs. Baltimore, gaining only 4.8 yards per attempt with one interception. He has his third head coach in as many seasons, but it will likely be Mayfield who is "fired" if things don't improve this year.
The Cowboys run defense improved after they drafted Leighton Vander Esch in 2018, but he missed much of last year due to a neck injury. Now a collarbone issue will cause Vander Esch to miss 6-8 weeks this season, putting the Cowboys run defense in another bad position.
The Broncos offensive line has struggled in recently seasons, particularly at tackle. Ja'Wuan James' optout was a big blow at right tackle, and the Broncos desperately need former first-round pick Garett Bolles to play better at left tackle.
The Packers surprised the football world by not addressing their receiver depth in the offseason after struggling in that area last season behind Davante Adams. Fortunately, Allen Lazard and Marquez Valdes-Scantling answered the call in Week 1 against Minnesota, both producing big games. The Packers are hopeful that group can continue to perform for Aaron Rodgers.
The Jaguars lost star pass rushers Calais Campbell and Yannick Ngakoue in the offseason. They do still have 2019 first-round pick Josh Allen, who performed well in his rookie season, but had only one sack in Week 1 vs. the Colts.
The Chiefs lost much of their cornerback depth in the offseason, and starter Bashaud Breeland is suspended for the first four games of the year. They were dealt another blow in Week 1 with top corner Charvarius Ward suffering a fractured hand, and are putting a lot of pressure on late-round rookies to perform.
The Raiders spent two early draft picks on rookies, including first-round pick Henry Ruggs. It's a good thing because 2019 free agent acquisition Tyrell Williams suffered a season-ending injury in training camp, and Ruggs also suffered a minor injury in Week 1. Derek Carr's wide receiver corps will be a work in progress again.
Miami drafted Tua Tagovailoa in the first round this year, but have gone with veteran Ryan Fitzgerald under center to start the season. It's inevitable that Tagovailoa will get his chance, but like most rookie quarterbacks, he will likely need time to get his feet wet.
After struggling in the secondary last season, the Vikings moved on from three of their top four corners last season. The pressure is on rookies Jeff Gladney and Cameron Dantzler to replace them, as well as third-year player Holton Hill. They didn't perform up to the task against the Packers in Week 1.
The Patriots replaced Tom Brady with former Panthers quarterback Cam Newton. Newton played well in Week 1, but his health remains a concern with several major injuries in recent seasons. New England fans have their fingers crossed that he can remain on the field.
Alonso suffered his third torn ACL late last season, and he was placed on the physically unable to perform list this year while he recovers. New Orleans' linebacker depth will be tested until Alonso returns.
Even after acquiring Leonard Williams via trade last year, the Giants struggled to rush the passer. They didn't make any notable pass rush additions in the offseason, though the team did bring back Markus Golden just before training camp. With a new coaching staff, they're hoping to generate more pressure this year.
Wide receiver was a problem last year for the Jets, and they replaced No. 1 receiver Robby Anderson with Breshad Perriman and second-round pick Denzel Mims. Unfortunately, Mims has already had injury issues, and Perriman had only 17 yards receiving in Week 1.
The offensive line is usually Philadelphia's biggest strength, but that will probably be different this year. Starters Brandon Brooks and Andre Dillard suffered season-ending injuries before the season started, and right tackle Lane Johnson also missed Week 1. Carson Wentz took a whopping eight sacks against Washington in Week 1, as a result.
James Conner was terrific in 2018 while replacing Le'Veon Bell, but he struggled last year due in large part to injuries. Now in a walk year, the Steelers need Conner to rebound this year, or 2019 draftee Benny Snell will get more work this year.
The 49ers lost Emmanuel Sanders in the offseason, and will be without 2019 breakout rookie Deebo Samuel for the first three games of 2020 due to a foot injury. Rookie first-round pick Brandon Aiyuk barely saw work in his first game, and the 49ers struggled to find any production from their wideouts in Week 1.
The Seahawks lost Jadeveon Clowney in the offseason, and did little in the offseason to replace him. The team is hoping for a rebound season from Jarran Reed, as well as more production from former first-round pick L.J. Collier. Seattle was only able to get two sacks against the Falcons in Week 1.
The Bucs came into the year with unproven third-year running back Ronald Jones as the starter. They've added insurance behind him with veterans Leonard Fournette and LeSean McCoy, but none of those players are a sure thing at this point. Jones averaged only 3.9 yards per carry in Week 1.
Tennessee moved on from starting cornerback Logan Ryan in the offseason, replacing him from second-round pick Kristian Fulton and veteran Johnathan Joseph. While the pass rush is clearly improved after signing Vic Beasley and Jadeveon Clowney, the cornerback situation could be fluid behind Malcolm Butler and Adoree' Jackson.
Washington selected Dwayne Haskins in the first round last year, but he had a poor rookie season. The result weren't much better in Week 1 against the Eagles, as Haskins threw for only 178 yards. If Haskins doesn't show improvement, the team could give veteran Alex Smith another shot.
Seth Trachtman is a fantasy sports expert and diehard Kansas City Chiefs fan still hoping for a Super Bowl win during his lifetime. He doesn't often Tweet, but when he does, you can find him on Twitter @sethroto.