Vikings QB J.J. McCarthy Diagnosed with Meniscus Tear

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Rookie McCarthy Out with Knee Injury

Vikings rookie QB J.J. McCarthy injured his meniscus in his preseason debut Saturday, which means Sam Darnold will start Week 1. What does it mean for Justin Jefferson and the rest of the Vikings?

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Tuesday brought unfortunate news, potentially giving us 2024's first season-ending injury of major fantasy significance (with all due respect to Falcons WR Rondale Moore). Our victim is Vikings QB J.J. McCarthy, the 21-year-old 10th overall pick who threw for 188 yards and two touchdowns Saturday in his NFL preseason debut but tore the meniscus in his right knee.

The good news? McCarthy might only need a meniscectomy, a procedure in which the damaged portion of the cartilage is removed. Players that have this surgery typically return to play less than two months later, and sometimes in as little as 3-4 weeks. If that's the case, McCarthy could be ready for a backup role by the end of September and then become a candidate to start at some point in October.

The bad news? McCarthy might instead need a meniscus repair, which entails stitching the damaged portion of the cartilage back into place and typically comes with a recovery timeline of 4-6 months. It's a better outcome for the long-term health of the knee, but McCarthy presumably would miss the entire season even if Minnesota made a playoff run (don't hold your breath on that one).

Doctors probably won't know which procedure makes sense until they've started operating, and in some cases the repair (with a longer recovery timeline) simply isn't an option. If it's a borderline case where both options are available, McCarthy and the Vikings will probably prefer the repair to the meniscectomy, considering he's the youngest QB in the NFL and Minnesota's the least talented team in a tough NFC North. The surgery is expected to happen by the end of this week, so it should only be a matter of days before we know if McCarthy is out for the season or projected to return in late September / October.

What it Means for McCarthy and Sam Darnold

Sam Darnold was already favored to start Week 1 and can now be locked into that role (unless he suffers a significant injury of his own before a Sept. 8 opener at the Giants). A one-drive sample in the preseason is meaningless, especially for a player with as much experience as Darnold, but optimists will note that he played well against the Raiders on Saturday, with three of his four incompletions appearing to hit the hands of a pass catcher (twice in the end zone).

We'll inevitably hear comparisons to Baker Mayfield, another top draft pick with some similar physical traits (besides height) who was initially promising in the NFL before flaming out. Mayfield, of course, got his career back on track in Tampa Bay last season, finishing slightly above league average for most passing efficiency stats and even winning a playoff game.

It's not a totally unreasonable comparison, as there's no doubt this is the best situation Darnold has ever been in. Kevin O'Connell is a good head coach and even better playcaller; Justin Jefferson and Jordan Addison are a phenomenal WR duo; the O-line returns four of five starters, including stud LT Christian Darrisaw and consistent RT Brian O'Neill; and TE T.J. Hockenson (knee) could be a major factor again in October or November. The Vikes lost No. 3 receiver K.J. Osborn this offseason, but they seem to really like Jalen Nailor as a little-known, in house replacement, and there's no question RB Aaron Jones is an upgrade on Alexander Mattison as a pass catcher.

The problem with the Mayfield comparison is that Mayfield's pre-2023 NFL track record included some genuine success, including 27 TD passes and 266.1 passing yards per game as a rookie (2018) and a 26:8 TD:INT for an 11-5 team in his third season (2020). Things in Cleveland fell apart in 2021, when Odell Beckham and Jarvis Landry combined for 14 missed games (and weren't all that good when they played). That was also probably Stefanski's worst year of an otherwise solid coaching career, featuring some unforced errors like giving Austin Hooper more snaps and routes than David Njoku (who had 130 more yards on eight fewer targets).

Darnold has nothing like Mayfield's 2018 or 2020 that he can point to, with his best effort being either his second pro season in 2019 (19:13 TD:INT, 232.6 ypg, 45.6 QBR over 13 starts) or a six-game cameo with the Panthers in 2022 (7:3 TD:INT, 8.2 YPA, two rush TDs.... but with six fumbles). For his career, Darnold has been well below average in nearly every efficiency stat, including completion percentage (59.7), YPA (6.7), TD rate (3.5 percent) and INT rate (3.1). 

Prior to last year, Mayfield had completed 61.4 percent of passes for 7.2 YPA, with a 4.5 percent TD rate and 2.8 percent INT rate, i.e., his career efficiency stats were mostly around around league average even after his 2022 stints with the Panthers and Rams dragged everything down a bit.

Darnold should post his best passing numbers yet in the best situation he's ever been in, but that might still mean below-average efficiency relative to starting QBs around the league. There's perhaps more hope for useful fantasy production than there is for quality real-life play, in part because O'Connell typically has been pretty aggressive throwing the ball and doesn't have a powerful or durable backfield with Jones and Ty Chandler. A team with Jones and Chandler in the backfield and Jefferson and Addison out wide probably isn't going to be among the league leaders in rush attempts, even if the QB is subpar. 

Also note that Darnold adds decent rushing stats, having averaged 17.7 to 18.5 yards per game each year from 2020 to 2022. He's run for 13 TDs in 56 career starts, which means we can reasonably expect 250-350 yards and 3-4 TDs over a 17-game sample (not that he'll necessarily make 17 starts).

If McCarthy ends up missing the entire season, the Vikings have Nick Mullens and Jarren Hall behind Darnold, which is much more interesting than what most teams have in the QB3 and QB4 spots. Mullens, as you may recall, has never struggled to move the ball and pile up yards. His problem, dating back to his time in San Francisco, has always been interceptions. Mullen has completed 65.8 percent of his passes for 8.0 YPA across a sample of 803 passes, which is Hall of Fame stuff until you see that only 4.1 percent of his passes have gone for TDs and 3.9 percent have been interceptions.

Hall, a 2023 fifth-round pick, was actually the first guy up after Kirk Cousins' injury last year, only to suffer a concussion on his second drive. Hall didn't get another shot until Week 16, at which point he turned the ball over twice in the first half and was replaced by Mullen for the second half. Hall may be the fastest guy in Minnesota's QB room, but he's already 26 years old and never went higher than 350 rushing yards or three TDs in a season at BYU. It's also fair to say that Minnesota's other moves at QB — bringing back Mullens, signing Darnold, drafting McCarthy — hint at zero confidence in Hall as even a backup.

What it Means for Minnesota's Pass Catchers and RBs

If McCarthy is out for the season it takes away Minnesota's ceiling scenario, in which the rookie becomes an instant standout and sparks unexpected stuff like a wild-card berth or Addison leaping toward WR1 fantasy range. We've seen enough of Darnold to know he won't excel; the hope is that he can be decent and have his stats propped up some by the good situation around him.

One might also argue that McCarthy missing the season removes Minnesota's floor scenario, in which an overmatched rookie makes a bunch of starts for evaluation purposes and completely tanks the team's offense. The counter-argument is that Darnold may also be capable of epic levels of stink, even in a good situation, though I don't quite buy it. Darnold is more likely to be normal bad, while McCarthy is more likely to be flat-out terrible (at least as a rookie).

A lot of fantasy players invested in Minnesota pass catchers figure to instinctively prefer the perception of a higher floor and lower ceiling that would come with McCarthy being ruled out for the season. I don't quite agree, but it does make more sense when discussing Jefferson, who we're drafting as a definite, every-week starter. With later picks like Addison, Jones and Hockenson the variance is probably preferable, because nearly all the teams that draft them will have similarly valued alternatives to man starting spots. As many before me have noted, upside is (almost) everything after the first 5-6 rounds of fantasy drafts.

In terms of team pass volume expectations, the Vikings will probably try to run a bit more than they did the past few years, at least if Jones stays healthy (a big 'if). But there's almost no chance of this team ranking near the bottom of the league in pass attempts, unless they also rank near the bottom in total snap volume (also unlikely). 

Lack of snaps can be a problem for really bad teams, or teams with really bad defenses (see: Seahawks 2021-23), but in the Vikings' case it probably won't be an issue even if their defense takes a step back and the shaky secondary gets exposed more than it did last season. While it didn't quite work out this way last year — and the Vikings defense was actually decent — Flores' extremely blitz-happy approach could mean struggles manifest in terms of big plays more so than repeated, lengthy drives.

We can even dream on a scenario in which Mullens' aggressive passing and Flores' aggressive blitzing put the Vikings in a bunch of games with tons of yards, touchdowns, turnovers and overall volume. They won't want to play that way out of the gate, but that's what it may deteriorate into if things go wrong with Darnold and/or the team in general.

Last year, the Vikings ranked fourth in pass rate over expected (PROE) in Cousins' eight starts, and then eighth from Week 9 onward. In 2022, the first year under O'Connell, they ranked seventh in PROE. In other words, we shouldn't expect a run-heavy offense in Minnesota anytime soon, even with Cousins replaced by question marks under center.