The image is frozen in Penina Nacua’s mind: a father, her husband, teaching their son Puka about football inside a truck.

But then young Puka would lose his father to diabetes in 2012. Lionel was 45. Puka, now a Rams’ rookie receiver, was 15 days from his 11th birthday.

“He was still young, but young enough to understand that his dad wasn’t there, and I feel like he always kept a lot of that inside,” Penina Nacua told Serby Says. “I don’t think he really opened up to talk about it until he got older. It was devastating for Puka because him and my husband were pretty close.

“There were times when I’d come to the truck, and I remember Puka sitting in the passenger seat and he’s got his iPad, and his dad would make him watch film. And he’s watching old players from way back during our time in the ’80s and ’90s. Puka would have to sit there, and he’d be watching film as my husband was taking him to a game. And they were my husband’s favorite players.”

Among them named Lawrence Taylor and Troy Polamalu. The oldest of six children was Chanel, the lone daughter, now 28. All hell broke loose following church for Kai, 27 now; Isaiah, now 26; Samson, 25; Puka, 22; and Tei, 18.

“My husband loved defense, he loved having his boys hitting each other,” Penina said. “He would have everybody suiting up and putting on the shoulder pads, and he’d make them go head-on, one-on-one. Whoever was the youngest was getting mauled, and that was Puka.”

Tough love was the standard. All the boys would go on to play football. “You got 10 seconds to get up,” Lionel would tell Puka. Puka never could bear staying down.

“Before the youngest child came, Puka was the youngest, and he sort of was the crybaby,” Penina said with a laugh. “He was very competitive, and he would be pissed if he lost in anything. He would be crying and stomping his feet going up the stairs. We still laugh about it and always bring it up when we get together. Anytime he lost, he’d be stomping his feet up the stairs and he’d be like, ‘I hate you guys, I hate my family,’ and we would all be laughing downstairs just going, ‘Yeah, yeah, get over it, you crybaby.’ ”

He got over it, all right. Even told his mother he would win two state championships at Orem High School in Utah.

“In high school, Puka was the kind of kid he would go eat with the kids who may not be the popular kids,” Penina said. “When it was team dinners on our Thursday nights, Puka always ate with his linemen, just laughing and getting to know them. He wasn’t about popularity, he never was looking to say, ‘Look at me.’ After the games, the coaches always left him time to talk to the team, and as the position coach. So there was the wide receiver coach, and then there was Puka.”

Then there was Puka at Washington, and then Puka at BYU. And now there is Puka shattering rookie receiving records for Sean McVay’s Rams.

“He has shown this freak athletic ability since Day 1,” Jets quarterback and childhood friend Zach Wilson told Serby Says. “I’ve always known he’s been a smooth route-runner, great ball skills, he’s been able to win on his routes, he’s obviously very smart.

“It’s no shock to me at all that he’s doing what he’s doing.”

It’s no shock to one of his coaches at BYU, and it’s no shock to one of his Rams teammates.

BYU offensive coordinator Aaron Roderick: “He can block. He can run short routes. He’s great after the catch. He can track the deep ball. There’s a lot of receivers even in the NFL that are kind of like one-trick ponies. Puka’s a guy who does everything.”

Rams RB Kyren Williams: “He’s a dog. Never too high, never too low, always in the moment. He’s always in Go mode.”

Cooper Kupp is scheduled to make his season debut, returning from a hamstring injury, Sunday against the Eagles. Kupp has mentored Nacua, and his quest to master his craft is impossible to miss.

“I would say they’re both technicians,” Williams told Serby Says by phone. “They both know how to get open, they both know how to catch the ball, they both know what to do after the catch.”

Roderick likes the comparison between the 6-foot-2, 194-pound Kupp and the 6-2, 205-pound Nacua.

“I think that’s a fair comparison, because Cooper Kupp is another one who has a really well-rounded game,” Roderick told Serby Says. “He’s a physical receiver, he makes plays down the field, but he’s also really good at running after the catch. They ask Cooper Kupp to do a lot in their run game. It appears to me that Puka is filling some of that Cooper Kupp role right now. I think when Cooper Kupp comes back, those two have a chance to really complement each other in a positive way.”

Nacua’s passion is contagious.

“He just loves football so much,” Roderick said. “When he comes in the room, you feel his energy. He’s not thinking about keeping himself healthy for his next contract or whatever. He lifts other people around him. He makes other people better by the way he approaches the game.”

Nacua’s 39 receptions and 501 yards and three games with 100-plus receiving yards are the most in a player’s first four games in NFL history. He has made a mockery of scouts and personnel experts who focused on his college injuries and 4.57 40 and allowed him to fall to the end of the fifth round as the 177th pick.

He has become a fan favorite. “It’s hard not to like the guy with a smile on his face,” Williams said.

It won’t go to his head. “I never let my kids ever think that they were bigger and better than everyone else,” Penina said.

Before Nacua caught the 22-yard game-winning touchdown in overtime last Sunday in Indianapolis, Williams recalled one specific play that he thinks epitomizes his teammate: No. 23 [Colts CB Kenny Moore] took a shot at him, and he got up and just signaled a first down. He ain’t gonna shy away from no contact, and he’s not gonna stay on the ground because of it.”

Of course he wouldn’t.

“I always remind my kids to not let their dad’s death go in vain because he worked so hard for you guys,” Penina said, “to remember that in all that they are doing and pursuing.”

She is Samoan, Lionel Hawaiian. Puka’s given name is Makea, but the family began calling him Puka when he started walking.

“He was this little, fat, chubby, Buddha-looking kid,” Penina said. “He had like no neck, and if I could find a picture of him and his dad, they were like twins. But he was the cutest thing. Everybody loved him, everybody wanted to hold him. If he didn’t know you, he didn’t want you holding him. He was always a mama’s boy anyway. I had to carry him everywhere, and he was hefty. “

Penina watched mama’s boy’s first NFL TD last week from her Provo, Utah, home with Chanel and her boyfriend, her granddaughter, Samson, Isaiah and Tei.

“We literally jumped off the couch, we were screaming, and we were just crying because watching Puka on TV and seeing him in his element and scoring that last touchdown to win the game,” Penina said, “that was just the sweetest moment to see. And we all felt like it was coming. Like we were all calling it already. I swear, the angels were there helping making sure he got in that end zone and he got it done.”

Puka was mobbed too quickly by his teammates, but the next time he gets in that end zone, Penina will be expecting Puka to point to the heavens, just to let Lionel Nacua know that he got it done.