National Football League

J.J. McCarthy and other NFL injuries that could impact 2024 season

Published Aug. 14, 2024 4:45 p.m. ET

All it took was one stellar preseason performance by rookie quarterback J.J. McCarthy to give the Vikings hope — both for their future and for this season.

Less than a week later, all that hope is gone.

That's how quickly fortunes can turn on unfortunate injuries in otherwise meaningless NFL preseason games — injuries such as the season-ending knee injury McCarthy suffered in his debut on Saturday night. One misstep can ruin a season before it even starts. One bad diagnosis can change the outlook for a team in an instant.

And the Vikings aren't the only ones suffering right now. There are injury-fueled panics in places like Los Angeles (Justin Herbert), San Francisco (Christian McCaffrey) and Kansas City (Hollywood Brown), too.

Not all preseason injuries will derail a playoff run or ruin an entire year. But there are still some big ones that are causing a lot of worry. Here's a look at eight who could deeply diminish expectations of their teams by the time they get to Week 1:

Minnesota Vikings QB J.J. McCarthy: There weren't high expectations for the Vikings, heading into a rebuilding season with a rookie quarterback. But there were high hopes for McCarthy, especially after he threw for 188 yards and two touchdowns in his debut against the Raiders. There were hopes that maybe he wouldn't have to suffer through the usual rookie growing pains. Now, those pains will have to wait until 2025, delaying the Vikings' return to contention even further. Even worse, their season is now in the hands of Sam Darnold, whose career has been a bust after the New York Jets took him with the third overall pick in 2018. Maybe Vikings coach Kevin O'Connell can revive the 27-year-old's career. It probably would have been a lot easier to develop the career of the 21-year-old McCarthy, though.

J.J. McCarthy out for the season with torn meniscus in right knee

Los Angeles Chargers QB Justin Herbert: For four years he has been one of the most talented and prolific quarterbacks in the NFL, and the general feeling is he's been dragged down by some truly terrible coaching. That was all supposed to change with the arrival of Jim Harbaugh, a proven winner in the NFL. But Herbert has been wearing a boot on his right foot all summer thanks to a plantar fasciitis injury, which has caused him to miss valuable time in a new offense and has put his opening day presence in doubt. And he doesn't just have a new offensive coordinator, he's also got a bunch of new receivers and running backs, too. He's had no time to work on chemistry with any of them. Obviously, the Chargers' playoff hopes diminish greatly if backup quarterback Easton Stick has to start in the regular season. But even if Herbert is back in time, who knows how long it will take him to round into form? With a tough September schedule that includes games against the Raiders, Steelers and Chiefs, that's a potential problem.

San Francisco 49ers RB Christian McCaffrey: History has shown that Kyle Shanahan's offense can run just fine with a committee of unheralded running backs, so if McCaffrey's calf injury keeps him out longer than the preseason, the 49ers will probably be OK. But "OK" isn't really the standard for a team that reached the Super Bowl last year and three straight NFC Championship Games. McCaffrey has been the engine of that offense since arriving in 2022 and is the player opposing defenses worry about the most. That takes a ton of pressure off quarterback Brock Purdy and makes things easier on his receivers. So yes, the 49ers can mount a strong ground game with some combination of Elijah Mitchell, rookie Isaac Guerendo, or maybe the recently signed Matt Brieda (Mitchell and Guerendo have been dealing with hamstring injuries of their own, too, by the way). But replacing the presence of McCaffrey is impossible. And if he's out or even limited for a while, that could make a big difference in the race with teams like the Eagles, Cowboys or Lions in the NFC.

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Detroit Lions RB Jahmyr Gibbs: It's true that Gibbs is only one half of the backfield duo for the Lions. But he was a dynamic part of it over the final 11 regular season games after he shook off an early season hamstring injury. He averaged 92 yards from scrimmage in those games and added 144 rushing yards and 94 receiving yards in three playoff games. The fact that he's battling a hamstring injury again is alarming, given how long it took him to shake it off last year. David Montgomery is certainly capable of carrying the running game short term. He rushed for 1,015 yards and 13 touchdowns in 14 games (and on 219 carries) last season. But it's the 1-2 punch that made the Lions a top-five rushing team and helped them to the NFC Championship Game. It's doubtful that Craig Reynolds or rookie Simone Vaki can duplicate what Gibbs brings.

Los Angeles Rams WR Puka Nacua: Most of the Rams' hopes this season were based on what the dynamic duo of Nacua and Cooper Kupp could do together if both receivers were fully healthy. Nacua's knee injury has put a damper on those hopes. It's not that Kupp can't carry a passing game by himself, assuming he can stay healthy. It's just that the two together make the Rams that much more dangerous in a conference loaded with offensive firepower. There might be some good news, though. Jordan Whittington, a sixth-round pick out of Texas, caught six passes for 74 yards in his preseason debut and impressed coach Sean McVay enough that he promised Whittington "is going to be a factor for us." McVay has a knack for turning unheralded receivers into stars. Maybe he's already found who's next.

Kansas City Chiefs WR Maurice "Hollywood" Brown: There are only two players the Chiefs could lose that would derail their Super Bowl plans: Patrick Mahomes or Travis Kelce. As long as both of them are healthy, the Chiefs are fine and a threat to win it all again. Still, they have been struggling to find a true No. 1 receiver since they got rid of Tyreek Hill two years ago. Brown was supposed to be that guy, but now he might miss a few regular season weeks with a shoulder injury. That thins out the ranks and probably puts more pressure on Rashee Rice, who might be facing an NFL suspension at some point. It also raises the stakes for rookie Xavier Worthy, a first-round pick out of Texas, and last year's second-rounder, Skyy Moore. Of course, Kelce is still the No. 1 option in the offense, so don't expect a big drop-off in Kansas City. But it's a stacked conference and they hoped Brown's addition would help create a little more separation from the other contenders.

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New York Giants WR Malik Nabers: When Nabers went down earlier this week with what is believed to be a mildly sprained ankle, panic set in among Giants fans — and for good reason. The rookie is, by far, the best receiver the Giants have had since they traded away Odell Beckham five years ago and he's had a spectacular summer. He's also viewed as the key to everything — the revival of the offense, the salvation of quarterback Daniel Jones, any slim playoff hopes the Giants might have. Without him, and with Saquon Barkley gone, it wouldn't be clear where the Giants will get their offense. The good news is Nabers' injury doesn't appear to be major. But it sure did rattle nerves because of the impact any prolonged absence by their top receiver could have.

Tennessee Titans WR DeAndre Hopkins: New Titans coach Brian Callahan has plans to really open up the offense, which is why they added Calvin Ridley and slot receiver Tyler Boyd this offseason. The hope was that their presence would do wonders for the 32-year-old Hopkins, who started to rediscover some of his old form last year. Hopkins is out with a knee injury, though, and not only might he miss the opener, but at his age, it could be a while before he's really back in form. That puts more pressure on Ridley. It also means the Titans will have to count heavily on Treylon Burks, their 2022 first-rounder who has been a disappointment and struggled to stay on the field. Ridley and Boyd are still a potent 1-2 punch. But as they work to develop young quarterback Will Levis, they could use all the help they can get.

Ralph Vacchiano is an NFL Reporter for FOX Sports. He spent the previous six years covering the Giants and Jets for SNY TV in New York, and before that, 16 years covering the Giants and the NFL for the New York Daily News. Follow him Twitter at @RalphVacchiano.