Four Downs: Can Lions' ground game carry on without Kerryon?

Allen Park — Here are four observations after having a night to ponder the Detroit Lions' 20-19 victory over the Carolina Panthers. 

First down

There’s plenty of speculation on the extent of Kerryon Johnson’s left knee injury after he exited the game late in the third quarter, but until the medical reports come back, we’re not going to know for sure.

If it’s on the severe end of the spectrum, sidelining the Lions rookie rusher for multiple weeks, or worst yet, the season, the offense could be in trouble.

Yes, the Lions’ passing attack came through in the clutch against the Panthers after Johnson exited, but before that, you could make a convincing argument Johnson was the Lions’ most important offensive player in the game and this entire season.

Well on his way to his third 100-yard performance on the season, the budding dual-threat standout is averaging 5.4 yards per carry on the year, while chipping in 32 receptions in the passing game.

More: Wojo: Lions' victory is costly if Kerryon Johnson is out

Without Johnson, Detroit’s newfound rushing attack is bound to struggle. With all due respect to LeGarrette Blount, Theo Riddick and the next-man-up mantra, the team’s other backfield options haven’t come close to providing the spark Johnson has brought.

Blount, 31, has been a disappointment in his first year with the Lions. After Sunday’s showing, seven carries netting 1 measly yard, his season-long average is down to an ugly 2.3 yards per pop. Riddick, who never has shown much as a ball carrier, has been used sparingly in that regard this year, hovering just below his career 3.4 YPC.

There’s also Zach Zenner, who returned to the Lions in great shape after breaking two bones in his back in the preseason finale, but like Riddick, the 3.6 yards per carry over the course of his young career doesn’t inspire optimism.

The Lions have worked out 11 running backs this season, most of who remain without a job. The most accomplished name from that list is Charles Sims, a former third-round pick who ran for nearly 1,000 yards during a four-year stretch in Tampa. Former Patriots running back Mike Gillislee is also out there waiting for a call, after playing four games with the Saints earlier this season.

That’s all to suggest it could get ugly without Johnson, who has been one of the NFL’s most elusive runners in his first season. If the absence is extended, it wouldn’t be surprising to see the Lions rank near the bottom of the league in rushing down the stretch, which once again will put the entire weight of the offense’s success on the shoulders of quarterback Matthew Stafford.

Second down

If there’s one area where the Lions are clearly trending in the right direction, it’s the way they're defending the run. For the third straight week, opponents have had a tough time moving the ball on the ground, despite the past two opponents having top-10 rushing offenses.

Even without A’Shawn Robinson, a premium run defender in the middle, the Lions continued to show improved understanding and execution of their run gap responsibilities against the Panthers, bottling up running back Christian McCaffrey and quarterback Cam Newton for 55 yards on 15 carries.

The week before, the run-happy Chicago Bears and their three-headed rushing threat mustered 2.5 yards per carry on 22 attempts. And going back one more week, take away Dalvin Cook’s 70-yard run — an inexcusable breakdown — and the Vikings backs averaged 2.6 yards the rest of the day.

The addition of Damon Harrison has been huge. The run-stuffing nose tackle eats up double teams as advertised, creating more opportunities for the linebackers to make plays. Jarrad Davis and Christian Jones have responded, elevating their play in the second level, resulting in the unit's marked improvement.

Third down

A week ago in this space we pondered that Ziggy Ansah might not be anything more than a third-down pass-rusher the rest of the season. And to start the Carolina game, that trend appeared to hold true, until the coaching staff pushed the pace with the former Pro Bowl defensive end down the stretch. In total, Ansah played a season-high 25 snaps, a few reps short of 50 percent of the defense’s overall workload.

For perspective, he's usually hovering around 60-65 percent when fully healthy.

That’s notable progress, and Ansah made his presence known against the Panthers with a sack, a pressure that led to another sack, and a hit on Newton that caused an incompletion and briefly knocked the quarterback out of the game.

Watching Ansah and Devon Kennard crush Newton’s pocket on a handful of third-down plays is what the Lions likely envisioned when they used the franchise tag to keep Ansah in Detroit for 2018. It’s unfortunate it’s worked out the way that it has, but if he can stay healthy down the stretch, it’s clear he still possess the ability to significantly impact a game.

Fourth down

Whether it’s age, scheme or some combination of the two, veteran safety Glover Quin continues to battle inconsistencies we’ve never seen during his time in Detroit. There were a pair of glaring mistakes against Carolina, poor angles on receptions that resulted in missed tackles and unsightly gains.

The other side of the equation is rookie Tracy Walker, who continues to make the most of his limited opportunities. That included his first career interception, at the end of the first half, when he ripped the ball away from receiver Curtis Samuel near midfield, ending a Panthers’ scoring threat.

The Lions have eased Walker into action all season, a logical developmental plan given the leap in competition from Louisiana-Lafayette, but it’s probably time to let out a little more line and see how he can handle a bigger workload. At this point, it’s becoming increasingly likely Quin won’t be back next season and it’s worth determining if Walker is truly a suitable replacement.

jdrogers@detroitnews.com

Twitter: @justin_rogers