The signings of Craig Robertson and Nate Stupar could be much more important to the Saints’ defense than anybody anticipates.

All it takes is an injury, a lesson the New Orleans linebacking corps learned all too well last season.

When Dannell Ellerbe went down, first with a toe injury and later with an injury to his groin, New Orleans often found itself scrambling at weak-side linebacker, a spot that became more of a revolving door than a position last season. Five linebackers started on the weak side at least once and logged more than 100 snaps; former backup Ramon Humber led the group with just 282 snaps overall.

New Orleans addressed the problem by getting younger, but not a whole lot less experienced, at the position. Robertson and Stupar, both 28, represent stable help behind the Saints’ presumed starting trio of Ellerbe, Stephone Anthony and free-agent pickup James Laurinaitis.

“I feel like we’ve got a good group of guys in our room,” Stupar said. “We’ll get together, hang out, have a nice group chat, talking, being connected. There’s nothing worse than if you don’t talk to the guys you play with and everyone’s out for themselves.”

Building chemistry is critical at a position with three new faces and players like Ellerbe and Michael Mauti who were in and out of the lineup last season. Anthony is the only constant, but the second-year player is moving to the strong side, making way for Laurinaitis to don the headset and run the defense from the middle.

Behind the top three, Robertson, Stupar and Mauti have to be ready to step into almost any spot.

“I’m learning everything,” Robertson said. “I’ve always been a guy, the more you can do, the more they can put you in different places, the better it is.”

For the most part, that’s all they can do right now.

NFL teams do not wear full pads or do any live contact during organized team activities, making it difficult for physical positions like offensive line, defensive line and linebacker to show their skills to the full extent.

But both players have obvious strengths. Robertson made more than 85 tackles in three of his first four seasons in the league, and he has the awareness in coverage to post six career interceptions. Stupar is an expert at setting the edge.

Both players, like Mauti, are also excellent weapons on special teams.

“Robertson and Stupar are both two linebackers that have played well in the kicking game,” Saints coach Sean Payton said. “That being said, we’re just in jerseys and helmets right now, so it’s tough to evaluate certain positions.”

New Orleans put the full-court press on to sign both players, beating out the Seattle Seahawks for Robertson and a couple of teams for Stupar. For Robertson, who played with a quarterback carousel in Cleveland, the presence of Drew Brees and a chance at the playoffs helped make his decision. The location also didn’t hurt; the Houston native makes his offseason home in Dallas.

Stupar was impressed by the Saints’ recruiting pitch; he also found himself drawn by the idea of familiarity after spending the past two seasons with the Falcons.

“I like the division,” Stupar said. “I like playing against Carolina, it’ll be good to play against Atlanta. I know those teams in and out, and I just like the rivalry.”

Veteran presence is important at linebacker, one of the most cerebral positions on the field.

By bringing in Robertson and Stupar to go with Laurinaitis, the Saints ensured there’s been plenty of football played by the men in the middle of Dennis Allen’s defense.

“You always tell your little stories about what happened when, when Nate was in Atlanta, when James was in St. Louis, when I was in Cleveland, we all have our stories,” Robertson said. “Now we can start getting our stories here.”