The pieces were always there. Putting them on the field together became a puzzle.

But when Tulane rolled out its nickel defensive package in Saturday’s 35-20 win over Southeastern Louisiana, the personnel and the system meshed for the first time this season.

The return of starting cornerback Taurean Nixon from a groin injury and the emergence of freshman cornerback Parry Nickerson allowed Tulane’s defensive staff to finally reveal their long-standing vision for the Green Wave secondary. Considering preseason All-American Lorenzo Doss already locked down one side of the field, and experienced safeties Darion Monroe and Sam Scofield were too valuable to sideline, the Green Wave (1-2) tinkered to find the perfect recipe.

The result was the best of both worlds.

“We had a plan in the summer to move Taurean inside all along,” Tulane coach Curtis Johnson said. “We really love Parry, but Taurean was hurt last week and so we had to play Monroe down (as the nickel). Taurean was probably our most injured (defensive back), and now he’s back full strength, and he’s physical and can run.

“We have three good nickels and corners, and now we can do some of the stuff we were able to do last year.”

Five weeks into the 2013 season, Tulane’s defense transformed into one of the best in school history when various pieces were put into the proper place. Now, as the Green Wave prepare for a trip Durham, N.C., and the offensively minded Duke Blue Devils (3-0) at 11:30 a.m. Saturday, it hopes to prove a corner has been turned again.

“We had some similar stuff last year early in the season where we gave up a lot of big plays. And we just had to get everything right before we played to the level we were supposed to,” Doss said. “I think that nickel spot makes a really big difference, and Nixon is perfect there.”

Getting the 6-foot, 183-pound senior to nickel opened up a variety of options. It first allowed the smaller Nickerson to stay outside and set up the more physical Nixon to become a roaming playmaker in the middle of the defense.

More importantly, it allowed Monroe, who started for two years at strong safety, to transition into his former role in the back end of the defense, where he can relay signals from the sidelines and communicate from a place of comfort. Even Monroe admitted some sideline calls were lost in translation when he was playing in unfamiliar territory, and too much of the burden shifted on Scofield.

“Sam can do it all, but he was basically forced to do everything I used to do and everything he did,” Monroe said. “I think we are just so comfortable back there together, and it clicked on Saturday. It just felt like home. When you add in the speed we have now, we are really looking good back there.”

The numbers bear it out. With sharply increased Tulane’s defensive speed, the Green Wave repeatedly stuffed a prolific Southeastern offense on the edges and in the middle. The Lions’ 271 total yards were a noteworthy drop from the 437 Georgia Tech and Tulsa averaged in wins over Tulane during the previous two weeks.

Both teams attacked Tulane on the edge.

Duke’s offense under David Cutcliffe has followed a similar script in averaging 513 yards per game, spreading defenses out with four-receiver sets and forcing tackles to be made in isolation and open space.

Getting the pieces of the Tulane personnel puzzle to fit is a necessary step in slowing the Blue Devils, who have scored more than 40 points in three of their past four games.

“We have more speed outside,” Johnson said of the Green Wave secondary. “When you have two safeties who have played as much as Scofield and Monroe, you like them playing safety. You don’t like moving guys out of position.

“With the way Taurean is playing, he’s playing well, and those two corners are playing better and better, it’s going to be an interesting second half of the season for us.”