Everyone has a theory as to why Chris Johnson and the Tennessee Titans’ running game remains stuck in neutral.

You hear everything ranging from the accountable – Titans players and coaches saying the execution on offense has to improve – to the ridiculous. Some fans and callers to talk radio, for example, suggest the offensive line is punishing Johnson by not blocking to the best of their capability for him.

I think we can safely throw that last excuse out the window. But for whatever reason, Johnson has not been able to get free for any run longer than nine yards this season through the first three games. And his paltry 98 yards rushing this season would have been a disappointing single game a couple of years ago.

Now $53 million richer, Johnson is an easy target. But, as the Titans will tell you, Johnson isn’t alone in culpability. The rest of the offense, especially the offensive line, shares in his frustration.

“Just inconsistency, that’s the easiest answer,” coach Mike Munchak says. “We start the game with two penalties on two good runs. His first or second run was an eight-yard run for a first down, and they called holding (on Leroy Harris). Then he comes back two plays later and for a 12-yard run and there is another hold (on Craig Stevens), and that’s just how it’s been going. It’s frustrating for all of us.”

Guard Jake Scott echoes the diagnosis.

“Poor execution, which is kind of a generic answer, but that’s kind of the sum total of it. We’re getting hats on hats and we’re not driving people off the line of scrimmage,” Scott offers.

Still, the symptoms show a deeper problem.

Fact is, the Titans’ running game hasn’t been the same since center Kevin Mawae left after the 2009 season, eventually retiring. After 16 years in the NFL, Mawae had lost something at the point of attack and in engaging his man on the line. But what takes time to develop, and can’t be replaced overnight, is the fact that Mawae knew every trick in the book for blocking and opening holes for a back.

Center Eugene Amano, who slid over from left guard when Mawae departed, and guard Leroy Harris, who moved into the starting lineup, are younger and stronger players, still thin on experience at their positions.

Could it be that Mawae’s savvy and experience were harder to replace than perhaps the Titans first believed?

Consider this: In two years with Mawae, Johnson ran for at least 100 yards 16 times in 31 games, including 11 consecutive games during his historic 2,006-yard season in 2009. True, the Titans had little to play for that year except getting Johnson his milestone. Johnson got an overinflated number of carries (358) to get to two grand, but the holes still had to be opened for him to run through.

Since his magical season, Johnson has had eight 100-yard games in 19 tries, all without Mawae. Not a great difference percentage-wise, but enough to ponder. Also, he has just two 100-yard games in his last nine.

As a team, the Titans were certainly run-heavy during Mawae’s four years in Tennessee, even before Johnson arrived in 2008. Tennessee averaged 138.8 yards per game in 2006, 131.8 in 2007, 137.4 in 2008, and finally 162 yards a game in 2009.

Last year, the Titans’ average dropped to 107.9 running yards per game. So far this season, the Titans are averaging 51.7.

And just in case you were wondering, the Titans averaged only 95.3 yards per game on the ground in 2005, the year before Mawae arrived.

The good thing, of course, and the Titans can consider this their saving grace for now, is the passing game has finally awakened with a rejuvenated Matt Hasselbeck at the controls. Even Munchak admits as much, though he still wants the run game to be straightened out.

“The script has been flipped as far as relying so much (more) on the pass game than we have in the past, where it used to be the run game,” Munchak says. “It’s been frustrating for all of us, but we will just keep working on it. We all know that (the run game has) got to be more productive if we are going to keep winning.”

Terry McCormick covers the Titans for TitanInsider.com and is the AFC blogger for National Football Post.