That's the question everyone is asking with the NFL's most explosive runner struggling this season. After watching some tape Johnson, there are some clear reasons for the decline in production:
Still recovering from lockout
After missing the entire offseason due to the lockout, Johnson sat out training camp over a contract dispute. When the Titans finally got an extension done with Johnson, he reported in less than ideal condition heading into the season.
Although Johnson worked extensively with a personal trainer during his time away, he certainly couldn't replicate the football-specific training that takes place on a daily basis at training camp. The lack of work has robbed him of his explosiveness. As a result, he looks nothing like the player who rushed for 4,598 yards and 34 touchdowns during his first three seasons. Over that span, Johnson averaged 5.0 yards per carry with 44 runs of 20-plus yards and 14 of 40-plus yards.
Johnson has only averaged 2.8 yards per carry and produced just two runs of 20-plus yards this season. While part of his dismal production can be attributed to poor conditioning, he also has failed to show the urgency and toughness that accompanied his previous running style. Whereas Johnson would run through arm tackles in the hole, he has routinely been taken down on initial contact in the first half of the season. He is the only back ranked among the top 50 rushers to average fewer than three yards per carry, and his penchant for negative runs has bogged down the offense.
In looking closely at Johnson's struggles, it appears that he is having difficulty reading his blocks at the point of attack. Rather than attack the line of scrimmage, he looks hesitant and indecisive. His uncertainty allows defenders to quickly corral him before he's able to get to the second level.
While experienced running backs are typically able to find creases with their eyes closed, Johnson's inability to find backside seams suggest his timing and execution are off.
The VY factor
One of the overlooked aspects of Johnson's production since he came into the league was the presence of Vince Young. The enigmatic signal-caller was a legitimate running threat, and his potential to sneak out the back door prevented defenses from focusing extensively on Johnson.
The Titans would use the threat of Young running to get Johnson loose by having the quarterback carry out bootleg fakes following handoffs to the frontside. This would keep the backside defensive end and linebacker from aggressively pursuing Johnson, which would leave huge seams for cutback runs. Johnson would often find those open cracks and blast into the secondary.
The stress of defending a potent rushing game with multiple threats is difficult, and CJ2K is certainly beginning to realize that fact in Tennessee.
O-line is failing to generate a push
As much as Johnson has been cited as the primary reason for the Titans' rushing woes, his blockers have failed to own the line of scrimmage. The interior trio of Eugene Amano, Leroy Harris and Jake Scott have really struggled to move defenders off the ball, which has prevented Johnson from getting to the second level unimpeded.
In the Titans' zone-based scheme, it is imperative that the line creates a collective push at the point of attack to provide cutback lanes for the runners.
By generating movement in the middle, Johnson is able to attack the line of scrimmage with his shoulders square and quickly get penetration. When executed properly, the combination of line movement and aggressive running produces big gains. This season, however, the crowd at the line of scrimmage has led Johnson to stop his feet prior to hitting the hole.
The Titans could remedy the problem by tweaking their scheme to feature some trap or pull concepts to help blockers get better angles. This could include using tight ends and H-Backs on kick-out blocks from various alignments to create seams on the backside. Johnson is still one of the best at exploding through holes on cutbacks when the option is there.
The Titans could also explore the possibility of shuffling their personnel to get a better combination of power blockers on the field. This might seem like a drastic approach considering they're 4-3, but fielding the league's worst rushing offense must prompt the coaching staff to examine all of its options.
Lack of commitment
While some would point to CJ2K's struggles as validation for the shift, he hasn't received a lot of carries. He has only two games with 20-plus rushes and averages only 15.3 attempts per game. Considering the fact that Johnson averaged 21.1 carries and had 18 games with 20-plus attempts over the past two seasons, his declining production is partially due to fewer opportunities.
Of course, Johnson's questionable conditioning led the Titans to curb his workload at the beginning of the season. However, he should be capable of carrying a full load at this point, and his past production should lead the Titans to put the ball in his hands. In looking at his only 100-yard performance of the season, it is interesting to note that he had 23 carries.
Although Johnson has been bottled up in the three games since that outing, it's time to see if he can regain his form with a heavier workload.