With the 2019 NFL draft and the bulk of free agency now in the past, the time for plugging major holes has passed. There are still some quality free agents floating around—and the trade market is still open—but most of the big moves that will be made this offseason have been made.

While depth charts still have to be settled, the rosters and front offices we see now around the league are largely the same ones we're going to see in September. Obviously, not every franchise is going to be a Super Bowl contender in 2019, but some have glaring weaknesses that are bigger than others.

While the New England Patriots will have to see if another patchwork offense is good enough to win a title, the Miami Dolphins don't even know who their starting quarterback is going to be this season.

The one thing the contenders and the unknowns have in common is that weaknesses do exist. Each team has a significant red flag that carries the potential to derail the upcoming season. We'll examine those here.

Arizona Cardinals: The Offensive Line

The Arizona Cardinals are hoping the change from Josh Rosen to Kyler Murray at quarterback will help open up the offense in 2019. However, a questionable offensive line could prevent Murray from having the desired impact.

The line—which allowed Rosen to be sacked 45 times in 14 games—may have been the biggest reason Arizona's last first-round quarterback struggled. Arizona added Marcus Gilbert and J.R. Sweezy in the offseason, but the line is still a work in progress.

Murray's escapability and Kliff Kingsbury's uptempo offense may mask some of the deficiencies along the line, but the fact remains that this is the biggest question mark on Arizona's roster. If the line doesn't improve as a unit, Murray may find it difficult to perform like an upgrade over Rosen in Year 1.

Atlanta Falcons: Two Rookies on the Offensive Line

The Atlanta Falcons used a pair of first-round picks on offensive linemen Chris Lindstrom and Kaleb McGary. Both could end up starting as rookies in 2019.

While there's no guarantee that Lindstrom or McGary will be liabilities in their first professional seasons, starting two rookies along the line is a risky proposition. Making the jump from collegiate competition to the NFL is a difficult challenge for any player, but it can be especially tough for linemen.

College offenses and pass-protection schemes are fundamentally different, which is why pro-ready offensive linemen are a rare commodity. Atlanta may have two first-year players protecting quarterback Matt Ryanthis season, and a lone mental error from either could have disastrous results.

Baltimore Ravens: A New-Look Offense

The run-based offense employed by the Baltimore Ravens in 2018 worked. Having Lamar Jackson as a dual-threat quarterback kept opposing defenses off balance and allowed Baltimore to surge late in the season toward an AFC North title.

However, the Ravens offense could look a lot different this year than it did during that run. Baltimore has a new offensive coordinator in Greg Roman, new skill-position players like Mark Ingram and Marquise Brown and, potentially, a new offensive identity.

"I think you'll be pleasantly surprised that Lamar is not going to be running 20 times a game," owner Steve Bisciotti said, per Jamison Hensley of ESPN.com. "That's not what this offense is about."

Does Jackson have the mental and physical tools to run a more traditional NFL offense? Absolutely. But there's a saying about not fixing things that are not broken, and the 2018 Ravens were dangerous because what they did offensively wasn't traditional.

Buffalo Bills: A Patchwork Receiving Corps

Like the Ravens, the Buffalo Bills are hoping their quarterback, Josh Allen, can make the second-year jump in 2019. Also like the Ravens, the Bills are hoping that Allen can become less of a running quarterback and utilize his arm talent more.

The question is whether the Bills have put enough receiving talent around Allen to accomplish this goal.

Buffalo revamped its receiving corps this offseason, bringing in the likes of John Brown, Cole Beasley and tight end Tyler Kroft. However, there isn't a true No. 1 receiver on the roster, and there's no telling if this patchwork collection of complementary receivers will be enough to push Allen to the next level as a passer.

Adding to the uncertainty is that Kroft is already out for the next several months with a broken foot.

Carolina Panthers: Cam Newton's Health

Quarterback Cam Newton wasn't the same MVP-caliber player late in the 2018 season as he struggled with a lingering shoulder issue, and the Carolina Panthers offense suffered.

There's at least a chance Newton will never again be the same player, which is a big red flag for the Panthers. He's currently recovering from shoulder surgery, and that can be problematic for quarterbacks—just ask Andrew Luck.

Add in the fact that offensive coordinator Norv Turner is still trying to tweak Newton's throwing mechanics, and there's a substantial amount of uncertainty surrounding Carolina's franchise quarterback heading into 2019.

Chicago Bears: Uncertainty at Kicker

The Chicago Bears saw their 2018 playoff run come crashing to an end when Cody Parkey's potential game-winning kick against the Philadelphia Eagles clanked off the goal post.

Kicker is one roster spot the Bears desperately want to improve in 2019.

However, Chicago still doesn't have a front-runner in the kicking competition with training camp rapidly approaching.

The Bears did recently narrow the field to Eddy Pineiro and Elliott Fry, waiving third kicker Chris Blewitt, but the starting job is still up for grabs—a red flag for a team that is fairly solidified at mo

Cincinnati Bengals: Linebacker

The Cincinnati Bengals parted with longtime defensive leader—and regular fine-payer—Vontaze Burfict in free agency. Cincinnati then missed out on linebacker Devin Bush in the draft when the Pittsburgh Steelers traded ahead of it to grab the Michigan product. They didn't add a linebacker until taking Germaine Pratt in Round 3.

This leaves Cincinnati's defense with a notable hole at the linebacker position.

The Bengals have some solid linebackers, like Nick Vigil and Preston Brown, but they don't have a true playmaker at the second level. This is a big red flag for a defense that ranked 29th against the run and dead last against the pass in 2018.

Cleveland Browns: A First-Time Head Coach

The Cleveland Browns have talent. For the first time in a long time, they also have genuine expectations heading into 2019. This means that new head coach Freddie Kitchens—who has never been a head coach before—is going to face a lot of pressure.

Kitchens is already getting a taste of this. He's had to answer questions about Odell Beckham Jr. skipping OTAs. He's been forced to play a large role in the installation of the offense despite the hiring of Todd Monken as offensive coordinator.

Once the regular season gets underway, there will be even more on Kitchens' plate. Can he handle the demands of running an entire team over the course of a full season while still building on the promise his offense showed in 2018? That's the biggest question hanging over Cleveland with the 2019 season fast approaching.

Dallas Cowboys: Potential Contract Distractions

While not every player allows his contract status to negatively impact the regular season, financial uncertainty can be a distraction. That's the reality of any job, especially one where injuries can alter a career in an instant.

This is why the Dallas Cowboys have to be wary about the ongoing contract discussions involving the team's three biggest offensive stars—Dak Prescott, Amari Cooper and Ezekiel Elliott.

Yes, players are usually going to do and say the right things, as Cooper has done this offseason.

"I'm more focused on actually playing and really earning the respect, and then the contract," he said, per Jon Machota of the Dallas Morning News.

However, if Cooper suddenly becomes timid when going over the middle or Prescott gets gun-shy staring down the pass rush in an effort to preserve their bodies, the Cowboys will be in danger of taking a step back offensively in 2019.

Denver Broncos: Joe Flacco's Recent Production

The Denver Broncos are hoping that veteran quarterback Joe Flacco can get the franchise back into playoff contention. This isn't an entirely unrealistic expectation, as Flacco is an experienced quarterback with a Super Bowl MVP on his resume. However, Flacco's recent production with the Ravens may have been a warning sign.

Flacco lost his starting job to rookie Lamar Jackson in 2018. He first missed time with a hip injury, and he missed another six games back in 2015 with a torn ACL. Even when healthy, though, Flacco has not been an elite quarterback in recent years. He hasn't even posted a passer rating above 90 since 2014.

That Baltimore left Flacco on the bench even after he was healthy last season is telling—and it could impact Flacco's performance in Denver. The presence of second-round pick Drew Lock could have Flacco looking over his shoulder all season long.

Detroit Lions: Offensive Health

By the end of the 2018 season, the Detroit Lions had running back Kerryon Johnson on injured reserve and were without wide receivers Marvin Jones and Kenny Golladay. While Johnson has been working with the team in minicamp. it's fair to wonder if he's back to 100 percent.

Golladay and Jones are still rehabbing their injuries, according to Dave Birkett of the Detroit Free Press.

These injuries on the offensive side of the ball could make it difficult for the Lions to fully install their offense ahead of the preseason. Worse yet, if these players aren't back to 100 percent by Week 1, Detroit's offense will suffer in games that actually matter. 

Green Bay Packers: Wide Receiver Depth

The Green Bay Packers have a legitimate No. 1 receiver in Davante Adams. They don't have much at the receiver position beyond that, though. Marquez Valdes-Scantling showed flashes as a No. 2 receiver in 2018, but the collection of Equanimeous St. Brown, Geronimo Allison and Jake Kumerow was underwhelming at best.

If the Packers are going to make a significant offensive jump under the direction of new coach Matt LaFleur, they're going to need more than just two good receivers. Unfortunately, Green Bay can't possibly know if it has that.

The Packers did little to address the wideout position in the offseason and actually parted with longtime standout Randall Cobb. While there is a possibility that one or more of these guys could emerge, receiver depth remains a concern for the time being.

Houston Texans: The Offensive Line

The Houston Texans watched quarterback Deshaun Watson get sacked 62 times in 2018. Sixty-two! That's alarming for a veteran quarterback with a track record of durability, let alone a second-year man coming off a torn ACL.

The Texans did draft Max Scharping and Tytus Howard to help address the line, but as unproven rookies, they'll merely compete for a starting job in 2019. There's no guarantee either will improve the line play out of the gate.

And until at least one of the rookies emerges as a viable upgrade, the offensive line is going to remain Houston's biggest problem area.

Indianapolis Colts: Secondary Depth

The Indianapolis Colts recently signed slot cornerback Kenny Moore to a contract extension. This helps ensure some stability in the secondary, but it doesn't improve the questionable depth Indianapolis has on the back end of its defense.

Moore is a solid cornerback. So is Pierre Desir, who was re-signed in the offseason. However, the Colts don't have another proven starter at cornerback, and safety Malik Hooker has struggled to stay healthy—he's played in just 21 games in two seasons. Indianapolis did draft cornerback Rock Ya-Sin in the second round out of Temple, but he'll have to earn his keep as a backup.