NEW ORLEANS — Less than an hour after beating the Houston Texans 40-33 on Sunday at the Superdome, veteran New Orleans Saints defensive end Will Smith sat alone at his cubicle, speaking in hushed, reverent tones about an old friend and teammate.

“You wonder, ‘Why that guy?’” Smith said. “Out of all the people, why that guy?’’

That guy is Steve Gleason, the 34-year-old ex-Saints special teams standout who has been diagnosed with amyotrophic lateral sclerosis — or ALS, also known as Lou Gherig’s disease.

It is a debilitating and ultimately fatal disease that scientific studies have shown increasing links between brain disease, such as dementia, and the frequency of concussions among football players.

Gleason served as honorary game captain on the fifth anniversary of the Saints’ 23-3 victory against the Atlanta Falcons on Sept. 25, 2006, the now-infamous game that marked the reopening of the Superdome in the aftermath of Hurricane Katrina.

Gleason played a memorable role in the outcome, blocking a punt by Michael Koenen that was recovered in the end zone for a touchdown by teammate Curtis Deloatch.

Gleason again lent a helping hand in Sunday’s victory against the Texans, first speaking to the team Saturday night at their airport hotel, then leading a sold-out Superdome in the pre-game chant of “Who Dat!’’

Afterward, inside the privacy of the winners locker room at the Superdome, the team presented Gleason with a game ball. Recently, the organization hung an expansive mural inside their practice facility commemorating Gleason’s blocked punt against the Falcons.

“It has been very emotional around here the past few days,’’ Smith said. “We really wanted to win that game for him. He’s one of the good guys. He loved to play football. He loved his teammates. He just loved life. It’s just very sad.’’

Smith spoke of Gleason in the past tense, a slip of the tongue, perhaps. But Gleason is clearly fighting for his life against a disease with no known cure.

He needed assistance from quarterback Drew Brees and Smith as he walked to midfield for the coin toss, the pre-game chant and back to the sideline.

“We had a ‘refuse to lose’ mentality today, kind of like Steve,’’ Saints linebacker Scott Shanle said. “Steve talked about that after the game. He compared life with football, saying things don’t always go the way you expect it to go or want it to go. But you still have control. It’s up to you to determine the outcome.

“I think as a team, we did a great job of honoring him today. I was proud that we won that game, so we could present the game ball to him at the end. When you go back to the play he made in 2006, at the reopening of the Superdome, that made a huge change in the organization in coach (Sean) Payton’s first year. We talk about building a foundation, and that was a huge brick in the foundation, that victory against Atlanta and that play by Steve Gleason.’’

Brees, too, acknowledged that Gleason provided the team and organization with an inspirational and motivational lift the past few days by his words and his mere presence.

“There has been a lot of emotion around here the last couple of days,’’ Brees said, “going back to last night at the team hotel. He had the most significant play in the history of this organization. More importantly, it’s the type of person that Steve Gleason is and what he represents as a person. You’re better off for having known him.

“Today was for a lot of things but none more so than for Steve Gleason.’’