It might not be fair to call Joe Lombardi a spy.

His identity is known, and he hides in plain sight. Lombardi is the current offensive coordinator for the Detroit Lions and New Orleans’ former quarterbacks coach. The Saints know who he is and what he’s about. He’ll be right there, out in the open, wearing a headset on the opposing sideline Sunday afternoon.

Yet the Saints are leery of him. They have no choice: Lombardi knows too much.

The tendencies, play calls, audibles — all of it is second-nature to him. He’s even lifted some of those things for his offense in Detroit.

Some of these things can’t be hidden. New Orleans knows this. Lombardi is going to see things on the field this week and know what’s coming next. It’s just the way it is.

But the things that can be camouflaged are being given an extra layer of cover this week. The Saints have to be safe.

“I think it might be simply, not so much the audibles, but the hand signals,” coach Sean Payton said. “You are already in a loud environment, so it’s not like they are necessarily being mindful of your hand signals that might mean a certain play.”

Signal stealing is not uncommon in the NFL. It’s a legal practice that most teams employ. If the opposition isn’t doing all it can to gain an edge, then the coach likely isn’t doing his job. The thinking is, if you get caught being lazy and the opposition is able to crack your code, it’s your fault.

It’s why coaches cover their mouths when they speak, body gestures and hand signals are used to call plays and why most home teams have their back to the press box, which makes it more difficult for an opposing coach in the box to key in on the sideline.

Stealing signs isn’t considered stealing at all in the NFL. It falls into the category of gamesmanship — as long as teams do not use recording devices to aid in their signal stealing, as the Patriots were famously caught doing during the 2007 season.

Commissioner Roger Goodell went on the record at the 2008 Super Bowl to state that he has no problem with the practice, and he said longtime coach Bill Parcells once told him a coach would have to be “stupid” to think the opposition isn’t constantly trying to hack his signals.

“I’m not sure there’s a coach in the league that doesn’t expect that their signals are being intercepted by opposing teams,” Goodell said.

How great an advantage a team can gain from engaging in this practice is debatable. It might take a whole game to crack a code, if it happens at all. And even if you know what a team’s signals mean, it might only help you on a handful of plays.

“It’s overrated,” Payton said. “It’s like when ‘The Brady Bunch’ had the playbook.”

One thing teams have been able to pick up on in the past few years, with players now wearing microphones on the field, is the offensive snap counts and the timing of a play. Payton says these things are not overrated, and he can simply go to file video and get everyone’s snap count since so much is now broadcast over the air.

“That information has become more readily available,” he said.

The league has become more paranoid over the years, but there was a time when coaches spent little time hiding their signals. Certain systems came with hand signals built in, and the teams running those systems saw no need to switch things up.

“(In) the West Coast offense for five years, there were about six teams that, if you saw the quarterback on film audible, he would get to a couple of different signals,” Payton said. “There was a period of time where they were universal and you would begin to get strains of it or different versions of it.”

Things are different now. Outside of being careful to make their calls and signal plays under the shadows of a play card or a towel, teams use decoys and have multiple signals for multiple things.

“Sometimes they are real, and sometimes they are not,” quarterback Drew Brees said. “I think you are always conscious when a guy that is very familiar with the system — the offense, the defense, whatever — goes elsewhere, but for the most part it is a new season (and) it’s a new team. There are a lot of new things and, when we go on the field, we try to control the game, we try to dictate to everybody else how the game is going to be played, so we don’t worry too much about it.”

But they do worry about it. And the Lions might want to think twice about how they’ve been signaling plays before the Saints come to town this week.

“Look, based on the offensive film I have seen, I think they are going to want to do the same,” Payton said. “In other words, you can see some similar signals.”

They’ve been warned.