10 biggest boom or bust NFL quarterbacks for 2018

Quarterback play often makes or breaks an NFL team’s season, and 2018 will be no different for 10 franchises in particular.

Whether it’s a stud signal-caller returning from injury, a young player entering a watershed moment in their career or a veteran needing to prove himself again, there are no shortage of storylines at the game’s most important position.

Let’s break down the 10 quarterbacks who are this year’s top boom-or-bust candidates, and why they qualify.

Andrew Luck, Indianapolis Colts
Is anyone fully confident in Luck’s right throwing shoulder? Well, he seems fine at least. CBS4’s Mike Chappell reported Luck completed 12 of 14 passes in 11-on-11 drills at Sunday’s practice, suggesting the arm and football mind are both sound.

How Luck holds up in the heat of competition against another team is another matter entirely. He missed all of last season and is in an AFC South division that’s a lot tougher and better since he last suited up.

Perhaps Luck balls out and is better than ever, thanks to a fortified offensive line led by top draft pick Quenton Nelson. However, he’s such a wild card coming off a long-term injury. There isn’t a lot of elite talent on the Colts roster, either, so Luck will have to do the heavy lifting to return Indianapolis to the playoffs.

Patrick Mahomes, Kansas City Chiefs
I believe he’s the biggest “boom” of the group, but there is a lot of immediate pressure on the second-year player with only one start under his belt. The Chiefs traded up to draft Mahomes 10th overall in 2017, and traded reigning NFL passer rating champion Alex Smith to Washington to fast-track the youngster’s starting tenure.

After five straight winning years and four playoff berths with Smith at the helm, expectations are high for the former Texas Tech standout. However, Mahomes seems up to the task. Former teammate Tamba Hali compared him to Brett Favre, which is no small compliment. That’s the type of arm and playmaking ability Mahomes brings to the gridiron.

With NFL rushing champ Kareem Hunt in the backfield and dynamic weapons like Travis Kelce, Tyreek Hill and Sammy Watkins to throw to, Mahomes has all the means at his disposal to be the next superstar at the position.

Blake Bortles, Jacksonville Jaguars
Super Bowl or bust. For a below-average quarterback, those are mighty expectations to handle, but that’s the case with Bortles, who’s signed a three-year contract extension.  As The MMQB’s Albert Breer pointed out in February, the Jaguars can bail on Bortles’ deal prior to 2019 for only an additional $6.5 million beyond what they owe him this year.

Many point to Bortles’ “impressive” postseason as the Jags went to the AFC title game. Was it really that impressive? He averaged just below seven yards per attempt and fewer than 200 yards passing per game, threw three touchdowns in three contests and completed 57.6 percent of his throws.

Thank goodness Jacksonville has running back Leonard Fournette and a stout defense to lean on. That will help Bortles as he tries to live up to his billing as the third overall pick in the 2014 draft, but he’s fallen short to date, and chances are, he will again in 2018.

Mitchell Trubisky, Chicago Bears
Playing in a division where your three counterparts are Aaron Rodgers, Matthew Stafford and Kirk Cousins can be intimidating. While Cousins is under a lot of pressure to deliver a Super Bowl for Minnesota, he’s established himself as a solid starter and has a high floor for the 2018 campaign, with a multi-year championship window.

Trubisky, a one-year college starter who was unspectacular last season (77.5 passer rating in 12 starts), is learning a new system under offensive guru Matt Nagy, previously the Chiefs’ offensive coordinator. After a three-interception practice this past Saturday, there’s reason to be alarmed about him.

He’s just not experienced and has big-market expectations for an historic franchise in the Windy City. Good luck with that. Trubisky has the biggest bust factor of anyone; the deck is stacked so high against him. Then again, if his quick release and nice physical skill set leads to a breakout season, Chicago will know he’s “the man” moving forward.

Case Keenum, Denver Broncos
On the heels of his career season with the Vikings, Keenum is being counted on to right the ship for the Broncos, who have missed the postseason the two years since winning Super Bowl 50, largely due to bad quarterback play.

Keenum is a proficient distributor who is decisive in his reads and avoids taking sacks. His contract is only two years long, so if he doesn’t live up to expectations in 2018, Denver could well draft a quarterback to compete with him and make him a trade chip the following year.

That means Keenum must shine right away. The problem is, the Chiefs are a perennial playoff team, and the Chargers are on the rise in the AFC West, so Keenum has his work cut out in his division alone. The Broncos’ schedule features only four of 16 games against playoff teams from last year, so that makes Keenum’s task more realistic.

Eli Manning, New York Giants
Despite holding the No. 2 overall pick in the NFL draft this year, the Giants opted not to take Manning’s eventual successor. They instead supplied him the best running back he’s had since Tiki Barber in Saquon Barkley.

A two-time Super Bowl MVP always gets the benefit of the doubt, yet Manning has led New York to only one playoff berth in the six seasons since his last championship. He’s also led the league in interceptions three times in his career.

Provided Barkley is the runner he’s expected to be and superstar receiver Odell Beckham Jr. can stay healthy, Manning could well have a big bounce-back 2018. If he flops, though, don’t be surprised to see the Giants move on to a new signal-caller next year.

Dak Prescott, Dallas Cowboys
Since he wasn’t drafted in the first round, Prescott is entering the penultimate year of his rookie contract. If he has a strong 2018 campaign, he could secure a big payday even before his first deal expires, but that’s a big “if.”

Prescott has little help in the receiving corps beyond slot man Cole Beasley and modest free-agent signing Allen Hurns. Although running back Ezekiel Elliott and a great offensive line are a big help, Prescott doesn’t have a ton of weapons to throw to.

The Cowboys are America’s Team, yet they haven’t advanced to the conference title game since after the 1995 season. It’s imperative that Prescott elevates the play of those around him and takes advantage of an ideal rushing attack to solidify himself as the franchise quarterback his breakout rookie year suggested he could be.

Marcus Mariota, Tennessee Titans
With five fourth-quarter comebacks this past season, including one in the playoffs, Mariota proved he could get it done in the clutch. What happened outside of those situations was beyond glamorous, though.

Mariota had 15 interceptions to 13 touchdowns in 2017 — a baffling regression in his third season. Now Luck is coming back for the Colts, Deshaun Watson returns from injury for Houston and the Jaguars still field an elite defense. That spells trouble for the Titans.

Now, if Mariota can play more consistently like he does in the game’s most critical moments, he’ll take a big stride toward being one of the league’s best field generals. He’s perhaps the hardest player to gauge among this 10.

Derek Carr, Oakland Raiders
The return of head coach Jon Gruden feel like it’s either going to be a huge hit or a big bust. There’s really no in-between when you sign a man who hasn’t coached in the NFL since 2008 to a 10-year contract.

Since it’s Gruden’s show — he’ll call the plays — Carr’s fate is tied to his coach’s. A career yards per attempt of 6.54 is underwhelming considering Carr has a cannon arm. Not only has he not made enough of his ability to vertically stretch the field, but Carr is also a better athlete than most realize, evident in his 4.69-second 40-yard dash.

Carr could stand to improvise a little more and take more downfield shots in 2018. Otherwise he may be stuck in neutral in Gruden’s old-school West Coast system, which relies on a precise, short passing game, the dink-and-dunk schematics that have prevented Carr from reaching his full potential.

Cam Newton, Carolina Panthers
At what point will it matter that Newton is below NFL accuracy standards? As soon as his massive frame is too beat up to take off and run as often, Newton will have to win more consistently from the pocket, which he’s struggled to do with a 58.5 percent career completion rate.

There’s no denying Newton is a threat as a ball-carrier. It’s a reason he’s a past NFL MVP and why his boom-or-bust floor is higher than anyone on this list.

That said, he could be an even more dynamic dual threat if he were a more precise passer. Lazy mechanics seem more to blame than arm talent, because Newton flashes the ability to fire the ball into tight windows on the regular — even with sloppy footwork.

Newton’s receiving corps is suspect as usual, and will require the likes of rookie first-round pick DJ Moore and second-year speedster Curtis Samuel to rise to the occasion. Carolina could be downright special if those two step up, allowing Newton to get the ball out more on underneath throws and avoid punishing hits he’ll already take in the running game.