Already trailing 14-3 before the end of the first quarter, the Arizona Cardinals needed to string together some positive plays in order to claw back into the ballgame. Mike McCoy, the Cardinals' embattled offensive coordinator, had struggled all season to establish a rhythm with rookie quarterback Josh Rosen and now had to do so against a formidable Denver Broncos defense. With the game quickly slipping away, McCoy surely understood he had no margin for error.
The Cardinals opened the drive with a B-gap run for David Johnson that ended behind the line of scrimmage. McCoy then dialed up an all-curl passing play that resulted in a Larry Fitzgerald catch just shy of the first-down marker. Facing third and short, McCoy ran J.J. Nelson on a slant route for Rosen's primary read with Fitzgerald running a flat route to open up the middle of the field. If executed correctly, Arizona would have its first third-down conversion of the night.
But like most of the Cardinals' season to that point, the play quickly fell apart. Broncos safety Will Parks knocked Nelson off his route and disrupted the timing with Rosen's throw, leaving the ball free for cornerback Chris Harris to swipe out of the air. A 53-yard interception return ensued, with Harris exchanging a high-five with a teammate just as he crossed the goal line.
Just seven weeks into the season, Arizona faced its first major crisis under first-year head coach Steve Wilks. His team looked overmatched, outmaneuvered and, most damningly, outcoached. The offense under McCoy managed a league-worst 82 points and ranked at the bottom of the conference in offensive efficiency. Rosen, the quarterback whom the Cardinals traded into the top 10 to acquire, struggled as he completed just 55 percent of his passes while throwing nearly twice as many interceptions as touchdowns. Meanwhile, Johnson averaged just 3.2 yards per carry, a full yard off his breakout 2016 season. By any objective measure, the Cardinals offense looked like a train wreck, one badly in need of a change.
Despite initially dismissing the notion of a staff shakeup, Wilks fired McCoy the following day, citing seven weeks of poor offensive production as the catalyst behind the move. McCoy also installed 38-year-old quarterbacks coach Byron Leftwich, a holdover from the previous year's coaching staff, as the Cardinals' new offensive coordinator. Leftwich didn't promise to reinvent the wheel in his new role, but he did make sure to put his offensive stalwarts in a better position to succeed. That included Johnson, who floundered under McCoy's unimaginative approach to the offensive backfield.
During Johnson's landmark 2016 campaign, the Cardinals ran him between the tackles on just 35 percent of his carries, according to NFL Next Gen Stats. That figure ballooned to nearly 60 percent under McCoy, contributing to Johnson's dismal efficiency. Leftwich sought to correct this immediately, cutting Johnson's inside-run rate to 43 percent in his first game as offensive coordinator. The running back responded with his finest performance of the season to that point (100 yards from scrimmage on 10 touches) and has continued to trend upward in the games since.
And despite Arizona's porous offensive line creating a bottleneck for the offense, Johnson has returned to normal in several key areas. Since the offensive-coordinator change, he has averaged 3.7 yards per carry after close-in (the point when the first defender comes within a yard of the ball carrier), a significant increase over his 3.0 clip under McCoy and right in line with his 3.6 mark in 2016. Johnson's big-run rate (rushes of 10 yards or more) has climbed a full point and a half since Leftwich took the reins. Most importantly, Johnson's successful-play rate has gone from 34.9 percent through the first seven weeks of the season to 46.5 since.
Meanwhile, Leftwich has reined in some of Rosen's worst tendencies. Under McCoy, Rosen too frequently targeted covered receivers in the end zone, completing just 28.6 percent of those attempts, according to NFL Next Gen Stats. Leftwich's tutelage has helped Rosen improve that figure to 44.4, a notch above the league average of 38.6. The Cardinals offense has become a more efficient scoring unit as a result, increasing their red-zone touchdown percentage from 63.6 under McCoy to 71.4 on the year.
At the same time, the Cardinals offense still lacks in other areas. The team still ranks dead last on a per drive basis in yards gained (21.2), points (2.1), plays (4.9), and time of possession (2:18). Some of the blame for those ongoing issues falls on the offensive line, which has an adjusted sack rate of 8.1 percent, according to Football Outsiders. Still, the NFL's best offensive coordinators have found ways to scheme around poor blocking, and Leftwich simply hasn't done enough to mask Arizona's deficiencies in that area.
Leftwich also hasn't augmented the Cardinals' offensive scheme with modern concepts. Now more than ever, NFL teams use pre-snap motion to help their quarterbacks identify coverages and scheme receivers open. Nearly 40 percent of all plays from scrimmage this season featured some kind of motion. That figure includes the increasingly popular jet sweep, a play that forces opposing teams to account for the horizontal dimension and, in turn, flattens the defense and creates more open space in which the offense can operate. The Los Angeles Rams and Kansas City Chiefs lead their respective conferences in scoring and, not coincidentally, each has run double-digit jet sweeps entering Week 13, according to Sports Info Solutions. Meanwhile, the Cardinals have run just four over the same stretch.
And in a season when the NFL's best teams attack the middle of the field more than ever, the Cardinals have fallen behind. Entering Week 14, the league's top three scoring offenses -- the Chiefs, Rams and New Orleans Saints -- have collectively targeted 58.9 percent of their passes between the field numbers. Those teams have combined to post a 123.8 passer rating on those throws, a full 10 points above their rating on passes outside the numbers and well above the overall leaguewide mark of 94.3.
Back in Arizona, Rosen's output looks decidedly different. The rookie has thrown between the field numbers on just 56.0 percent of his attempts, one of the lowest rates in the league among those with at least 250 passes. That figure has effectively remained unchanged under Leftwich (55.9 percent). Considering the stark contrast between Rosen's passer rating on attempts inside the numbers (82.9) versus outside them (58.9), Leftwich should have done more schematically to funnel throws over the middle.
The Cardinals placed Leftwich in an unenviable position. The mid-season staff shakeup forced the first-time play-caller to adjust to a new job and increased responsibility on the fly while dealing with a young, limited group of offensive players. Few would succeed in that situation, especially those in just their third year of coaching.
Still, the disparity between the NFL's top offenses and the one run by Leftwich highlight the areas in which he needs to evolve. The Cardinals have taken some corrective measures since he took over for McCoy, but they still trail their contemporaries in terms of motion and scheming around their roster's strengths. Given the talent gap between Arizona's offensive personnel and that of the top teams in the league, Leftwich has no justification for running such a comparatively straightforward scheme.
Even so, Leftwich has probably shown enough progress to merit a full season in charge of an offense. Whether he will receive that opportunity in Arizona remains unclear. The Cardinals currently own the second-worst record in the NFC and could realistically lose every game left on their schedule. Wilks will have a hard time surviving into next year should that scenario unfold, and with general manager Steve Keim potentially on the hot seat himself, the entire organization might undergo a reset in the coming months.
But Leftwich can't fixate on his future in the desert now. Until the season concludes, he must prove to Cardinals brass that his work thus far, as well as his long-term potential as a coach, warrant an extended look into 2019. The next four weeks will serve as his audition.