NASHVILLE, Tenn. -- The Tennessee Titans' shift from a 4-3 front to a 3-4 alignment doesn't come with a plea for patience.

Changing the shape of a defense isn't a multiple-year process in today's NFL, and the Titans don't have to look far for evidence of that.

In 2010, the Houston Texans hired Wade Phillips as their defensive coordinator. As he had many times before, he remodeled a 4-3 into his 3-4, installed a new mindset and got new results. The Texans ranked second in defensive yardage and won the AFC South.

In 2012, the Indianapolis Colts hired Chuck Pagano as their head coach. He and defensive coordinator Greg Manusky converted a 4-3 into a 3-4. While they didn't mirror the Texans' statistical success from two years earlier, the defense was good enough for the Colts to win a wild-card spot.

"Saying it's going to take time and that stuff, that's to help personnel people and coaches keep their jobs," Wade Phillips said of switching your defensive front. "You've got to win now." Troy Taormina/USA TODAY Sports

Neither Phillips nor Pagano expected the luxury of a transitional year, in which he could hit pause on expectations. Phillips didn't hesitate to flip things and engineered another big first-year turnaround. Pagano talked about the need to be a hybrid defense in transition. They expected results, and got enough for their teams to go to the playoffs.

Along with the Titans, the Falcons (moving to 3-4) and the Bills (to a 4-3) are changing defensive fronts and philosophies.

Phillips believes fans in any of those markets should be wary of any talk from the brass about the need for patience.

"That's protecting yourself," said Phillips, who lost his job when Houston hired Bill O'Brien and is currently out of the league. "It doesn't matter in this league, they are going to fire you anyway if you don't get it done.

"Saying it's going to take time and that stuff, that's to help personnel people and coaches keep their jobs. You've got to win now. You've got to change things. Usually you're coming in to fix something. "

Perhaps a switch from a straightforward 4-3 to the more old-school, two-gap 3-4 like the Pittsburgh Steelers run would make for a time-consuming changeover. But while 3-4s are on the rise, more are in line with ones Phillips ran as coordinator or coach in New Orleans, Philadelphia, Denver, Buffalo, Atlanta, San Diego, Dallas and Houston. They are schemes with edge setting, pass-rushing outside linebackers who do not require a mammoth nose tackle and don't ask the three down lineman to account for two gaps.

Under Ken Whisenhunt in Tennessee, defensive coordinator Ray Horton's 3-4 base front will seek to create confusion about who is rushing and from where. There will be enough two-gapping to make offenses have to look out for it, but it won't be the default or the norm.

What sense would it make for Whisenhunt, Horton and defensive line coach Giff Smith to ask Jurrell Casey, who was the Titans best defense player last season and had 10.5 sacks, work to occupy defenders and allow linebackers behind him to make the plays?

"He's a heck of a player," Smith said. "I told Case when we got here, he'll actually get more one-on-one situations out of our spacing than he would out of a 4-3 spacing. ... Our deal is to get him in as many as we can. I think he puts stress on offensive linemen, he's a difficult guy to block. ...

"It's more of a loaded box where you have to man up. It looks like single coverage on the outside whereas when you're in 4-3 spacing, sometimes your backers cheat back to 5, 5 1/2 yards and they're on the second level and you've only got four guys up front. They can bump, they can chip, they can double (to slow you down). Where in a 3-4 with what Ray is doing and walking guys up, they have to man and they don't have the time to be able to chip and climb."

New Tennessee Titans defensive coordinator Ray Horton will embrace the players he inherited. AP Photo/Mark Duncan

If the Titans have enough good players as they believe they do, then they should be able to get them in positions to maximize their talents.

Whisenhunt said schematically the 2013 Titans ran hundreds of plays in the exact same scheme that will now be their base. Holdover guys "at least have some basis as a starting point," he said.

"The old-school ways of playing the 3-4, schematically that was a difficult defense to play," Whisenhunt said. "Just from a standpoint of the two-gap and having the right guys like Carl Banks and Lawrence Taylor outside.

"It was a different defense than we're running. We're a more aggressive type of defense that is going to give you multiple looks. It's not a 3-4, two-gap defense. But when you say 3-4 defense that's the perception of a lot of people."

St. Louis Rams coach Jeff Fisher, a 4-3 guy who ran the scheme for his 16-plus seasons coaching the Oilers/Titans, said the franchise's switch "is moving a guy here and there, it's not as hard as people speculate."

Both Whisenhunt and Phillips share a philosophy that helps make an altered approach easier: It's more about the players than the scheme.

Phillips points to three different approaches with three different players all aiming for the same result: ownership of one of the A gaps in the middle of the line.

"Ted Washington was 340 pounds in Buffalo, he played nose but we play a one-gap defense," Phillips said. "We played him in the middle of the center and let him take the center and just control his gap. Jamal Williams was a power guy (in San Diego), we offset him and let him basically knock the center back and take the same gap. Then I had Greg Kragen in Denver, another Pro Bowler. He was a smaller guy, so we stunted him to the gap.

"They all played the same position, had the same assignment, but played it differently."

We don't yet know what the responsibilities of certain positions will entail in Horton's defense. But he can have wrinkles that make things easy for certain players.

Derrick Morgan and Akeem Ayers look to be the two primary strong outside linebackers. Morgan's been a 4-3 end and Ayers hasn't fared particularly well in space so far in the NFL. In Phillips' system, the only coverage they'd have been asked to play would have been in the flat.

"It's what the players can do, not what you can think of," Phillips said. "Some people are so scheme-oriented that they block people out and say, ‘Hey, we can't use this guy even though he's a good player.'"

The Titans are being inclusive, not exclusive.

Horton and his staff are embracing what they inherited -- much of which may have been insufficiently coached by the previous staff. They've also added a nice splash of 3-4 help: Linebackers Shaun Phillips, Wesley Woodyard and fifth-rounder Avery Williamson and linemen Al Woods and fourth-rounder DaQuan Jones.

Whisenhunt and Horton aren't looking at Andrew Luck or the top offensive players they will be trying to slow this year and thinking, in another year or two this scheme will be equipped and stocked to get the job done.

"Our expectation is to have success defensively this year," Whisenhunt said. "Will we get better at it in time? I think you get better at anything when you have more reps with it. But it doesn't mean I don't feel like we'll play good defense this year."