For maybe the first time in his Tulane career, linebacker Nico Marley got mad Saturday.

With the Green Wave comfortably ahead of Southeastern Louisiana in the fourth quarter, he celebrated a goal-line stop on third down by flexing his muscles in what coach Curtis Johnson described as a Superman pose. A flag flew for unsportsmanlike conduct. Marley protested vigorously, and Southeastern scored on the next play.

His anger was partly directed inward for getting flagged twice in three plays — his personal foul penalty already had given the Lions an automatic first down at the 1 — and partly aimed at the officials for what he thought was a bad call. Either way, he acted out of character.

“That was the maddest I’ve ever seen him,” safety Darion Monroe said. “I didn’t like the call either. I felt like he was doing it toward our sideline and there wasn’t any target. That’s the first time I’ve seen him upset. He’s pretty mellow all the time.”

Around Tulane, Marley’s even-keeled personality is as legendary as his playmaking ability. That ability turned the (generously listed) 5-foot-9, 207-pound grandson of reggae superstar Bob Marley and son of former Miami Hurricanes star Rohan Marley into the Conference USA co-freshman of the year in 2013.

Soon after his “outburst” against Southeastern, Marley was back to himself.

“I don’t stress anything, man,” he said. “Nothing really stresses me out. I don’t let things get to me.”

That trait is as much the secret to his surprising success as his speed and intensity. Offered a scholarship by no FBS school other than Tulane because of his size, he started 12 games as a true freshman and made 67 tackles, including 10 behind the line of scrimmage.

Through three games this year, he has 22 tackles and three stops for losses. He added an interception and a sack against Southeastern, earning Defensive Player of the Week honors from the Louisiana Sports Writers Association. He was part of a seven-page Sept. 15 Sports Illustrated feature on the Marley family that traversed their coffee field in Jamaica to the influence Bob Marley had on his descendants.

Nico Marley arrived in New Orleans with a plan and a purpose and has executed it to perfection. No Tulane player spends more time in the video room than Marley. No teammate goes harder in practice on every play than Marley.

The product is a guy who plays with reckless abandon while remaining under control, a rare combination.

“I just give as much effort as I can while staying in the scheme of the defense and doing what the coaches ask,” he said. “I use my eyes. I’m smart. The coaches tell me to look at the ball and look at the call.”

More often than not, he finds what he is looking for. He majors in tackles on the field and in business off the field, overcoming any hurdles in both.

“He’s confident, he’s strong-minded and he’s strong-willed,” said Rohan Marley, who led Miami with 95 tackles in 1993 while playing alongside Pro Football Hall of Famer Warren Sapp and future Hall of Famer Ray Lewis, among other all-world talents. “He just understands life and knowing how to be mature. He understands responsibility.”

How he turned out that way is a matter of conjecture.

Certainly, the Rastafarian-influenced heritage of Bob Marley played a part — Monroe said everyone he has met from the Marley family, with the exception of the energetic Rohan, is as mellow as Nico.

Rohan credits Nico’s mom, Geraldine Khawley, with raising him right in south Florida. The couple divorced a year after Nico was born, a few days after Rohan’s last game with Miami.

Some characteristics, though, are just inherent traits.

“My mom wasn’t strict,” he added. “She told me what not to do, but she didn’t say you can’t go out. She always trusted me, so I got to do what I wanted. I just try not to get in trouble. I see no purpose in getting in trouble.”

Rohan recalled the biggest issue Nico had as a kid was getting home a little late on his dirt bike. He never heard about him getting in a fight.

“I remember one time he was in school and some kid did something to a girl,” Rohan said. “He said, ‘Dad, what should I do? Should I say something to him?’ I said stand up for the girl; tell him that he’s not right to do that — but don’t fight, don’t get yourself in trouble. And he did that. That’s how he is.”

Although they share the same playing style, the difference in father and son is evident in their speech. Nico speaks carefully, parsing out words like he is trying to conserve them. Rohan lets it rip.

“We just love to channel that energy to try to knock someone’s head off,” Rohan said. “I just remember every day going out there and trying to hurt somebody. I wanted every tackle to be a big tackle, to knock the guy out of the game.”

Nico is just trying to win. Having helped Tulane to its first bowl bid since 2002 last year, he took the Wave’s 0-2 start this season seriously and was visibly relieved after it held on to beat Southeastern.

Although Marley does not say much, coach Curtis Johnson still labeled him the vocal leader on the team because his words carry weight. When a little man plays big, he attracts plenty of followers.

“He is fearless,” Johnson said. “He brings the right attitude every day. He looks like he’s up against a 7-footer, and he knocks them back every time. He walked in here with a chip on his shoulder.”

The only thing is, that chip is more like a computer chip. Marley knows where every player at every position is supposed to be on defense, and linebackers coach/co-defensive coordinator Jon Sumrall said Marley has taken over some position meetings to tutor his teammates.

Because he is the way he is, everyone on the team is mad about him.

“He’s such a well-rounded individual,” Sumrall said. “He’s an extremely intelligent, very passionate, just trustworthy, dependable likable guy. He’s got so many characteristics that will make anybody successful in anything they want to do.”