We interrupt this talk about the problems with the Tennessee Titans running game to remind everyone that the NFL is still a quarterback-driven league.

And if the Tennessee Titans didn’t already know this, they certainly do now.

While the run game continues to be a backdrop of why the team has fallen to 3-3 with two straight losses, the absence of Jake Locker is probably the bigger issue.

Here’s why.

At the beginning of the 2013 season, one of the biggest questions was whether Locker could be a capable NFL quarterback who could do more than just be a caretaker in the offense.

After a very conservative beginning in the win over Pittsburgh, Locker made enough strides that the talk soon transformed into how much he had improved and developed in such a short amount of time.

While Locker might not ever be the equal of Peyton Manning or Drew Brees, he was demonstrating that he is the type of quarterback a team cannot only win with, but even occasionally win because of.

The best evidence came in the waning moments of the Titans’ victory against the San Diego Chargers at LP Field. No timeouts, 94 yards in 1:50 for the game-winning touchdown. Impressive, no matter how you slice it.

The best part of Locker’s play, no doubt, was the zero in the interception column. It allowed the Titans the chance to potentially win every week. And he was making enough clutch plays in the passing game that the Titans didn’t have to rely on the running game as much as first thought.

Then came his hip and knee injury against the Jets in a win that lifted the Titans to 3-1.

Much of that early-season optimism has faded in the past two weeks as the offense has been plagued by turnovers and the inability to run the football.

Not all of the blame lies with backup Ryan Fitzpatrick, though he, by all accounts (even his own), has not played well in his first two starts filling in for Locker. Four interceptions in two games says enough.

Tennessee Titans quarterback Ryan Fitzpatrick has had his problems subbing for Jake Locker, as this dropped snap from center demonstrates.

-- Ap Photo/Elaine Thompson

It’s not a knock at Fitzpatrick, but – as the saying goes – he is what he is, a streaky journeyman quarterback capable of playing extremely well or badly. He’s not Matt Cassel, Chad Henne or Kevin Kolb, all of whom have had their good moments and bad as NFL quarterbacks.

Occasionally, a team will catch the proverbial lightning in a bottle with a lesser heralded quarterback, but it’s not the norm in the NFL.

The reason the Titans stand 3-3 instead of 4-2 or even 5-1 is due to Fitzpatrick’s struggles and the woes that have arisen in the run game, problems have been exposed and magnified since Locker was injured.

While Coach Mike Munchak didn’t directly tie the loss of Locker to the struggles in the running game, it is probably not mere coincidence that the rushing attack went south about the same time Locker went out.

Locker was doing enough in the passing game to keep opponents somewhat honest as they keyed on stopping the run.

Without Locker, the Titans needed the running game to be better in order to take pressure off Fitzpatrick. Instead, both the run game and Fitzpatrick have succumbed to the added weight on their shoulders.

“When you lose your quarterback, your best player, when you lose your leader, others guys have got to step up, and I thought we’d run the ball better,” Munchak says. “We need to do that to help Fitzy there, and we haven’t done that.”

Munchak admits his team’s running woes have put more on Fitzpatrick than necessary.

The formula for victory for the Titans in 2013 required all three parts of the equation – Locker, the running game and the defense – to contribute each week. And with Locker out, the other two parts of the formula were expected to pick up the slack.

The defense has done its job, but the running game has been exposed. Defenses now focus even more on slowing Chris Johnson without the threat of Locker beating them either with a pass or a scramble.

Even for team like the Titans, which wants to run the football and needs to run the football to be successful, Locker’s absence proves that the NFL is still a quarterback-driven league.

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