CHARLOTTE, N.C. -- NFL teams that passed on defensive tackle Star Lotulelei in the 2013 draft are finding out the hard way that the Carolina Panthers rookie, indeed, has a good heart.

A big one, too.

In many ways, the former University of Utah standout is becoming the heart of Carolina's front four.

“He’s not a star,” defensive end Greg Hardy told The Charlotte Observer after Sunday's 38-0 victory over the New York Giants. “He’s a superstar. And this superstar is a beast. I see some crazy things for his future. When and if he does keep developing, he’s going to be unstoppable.”

Lotulelei was considered the top-rated player in the draft by many before an echocardiogram administered before the NFL scouting combine in February revealed that his left ventricle was operating at just 44 percent -- well below the normal range of 55 to 70 percent.

A pre-draft test of Star Lotulelei's heart scared off some teams. But the Panthers liked what they saw, and now they love what he's doing for them. Tom Szczerbowski/Getty Images

A test administered soon after the combine reportedly led doctors to believe the initial test might have been caused by a virus. Still, many teams remained wary.

"All the time I felt fine, but at the same time, I could understand why a lot of teams wouldn't want to take that risk,” said Lotulelei, who is as humble as any player you'll find. "I'm just lucky this team took that risk.”

Carolina general manager Dave Gettleman and coach Ron Rivera didn't consider it a risk. When the Panthers' pick came up at No. 14, they needed only 90 seconds to select the 6-foot-2, 315-pound man-child.

"What Star does, he impacts the game on every snap in terms of the run game, pass game,” Gettleman said at the time.

Lotulelei hasn't disappointed. He has played well enough in his first three games to warrant early consideration for NFL Defensive Rookie of the Year, an award won by Carolina middle linebacker Luke Kuechly in 2012.

If he keeps improving, Lotulelei has a chance to rank as the best defensive tackle in team history. Kris Jenkins, drafted by the team in 2001, would be his closest competition.

"He's a big part of what we're doing right now,” defensive end Charles Johnson said. "The sky's the limit. We plan on him to get better.”

Lotulelei had his first NFL sack, one of six by the front four, in Sunday's victory. But sacks aren't the measure of his success so far. It's the way he demands double-teams, the way he penetrates into the opposing team's backfield to create chaos.

"He's real disruptive,” Kuechly said. "That's the thing you notice the most. And that makes everything easier for the rest of us.”

That didn't come through in Lotulelei's pre-draft workouts. He was not at peak condition after taking time off after the echocardiogram and ensuing tests.

"It was a very average workout,” Rivera said.

But when Rivera turned on tape of Lotulelei against USC and other big-time programs, he couldn't take his eyes off the domination.

"You can't hide from the tape,” Rivera said. "The young man dominated teams like [Southern California]. That's what we were more impressed with than anything else.”

Other teams ahead of Carolina in the draft probably are wishing they had relied more on that than a medical report.

"It's true for a lot of positions,” Rivera said. "You hear something, you see something, somebody says something and next thing you know, nobody wants to touch the player with that pick.”

As a result, Carolina got a Star who quickly is becoming a star.

"Superstar, baby,” Hardy said. "And he's humble about it. He's down to earth, he wants to work, and that's what makes a star.”