When John Marino first joined the Penguins organization this past summer after being acquired from Edmonton for a 2021 sixth-round draft pick, he said he wanted to work on the offensive side of his game.

"Work on my shot and little things on the offensive blue line where I can contribute and get more points, stuff like that," he said.

Marino, who was originally drafted by the Oilers in the sixth round (154th overall) in 2015, has certainly done that since making Pittsburgh's roster out of training camp.

The 22-year-old rookie defenseman has 13 points (3G-10A) in 29 NHL games, surpassing the 11 points (3G-8A) he put up in 28 NCAA games in his junior season at Harvard.

"Sometimes that's just kind of how it goes," Marino said. "Sometimes you get lucky bounces, sometimes the puck just finds the back of the net and sometimes it doesn't. So I think there's going to be stretches where you don't want to get too high or too low. Just try to stay even-keel."

Marino has quietly become one of the league's best rookie defensemen in a talented group that includes Colorado's Cale Makar, Vancouver's Quinn Hughes and his former Harvard teammate Adam Fox with the New York Rangers.

Marino, who recently had a six-game point streak from Nov. 16-27, ranks fourth in scoring among rookie defensemen after those three.

"It's interesting when you watch the transition of different players that come from college to the pros," Penguins head coach Mike Sullivan said. "With some guys, their games for whatever reason are better suited for the pro style of play. And he might be one of those guys."

The learning curve at the NHL level is usually steep for defensemen. It's truly remarkable that not only has Marino been able to handle himself defensively while playing alongside Kris Letang and going up against the other team's best players for the first time; but he has been able to contribute offensively as well without sacrificing anything from his game.

"He's adjusted to the pace of play, how quickly the players think the game at this level," Sullivan said. "A lot of times that's the biggest jump - players at this level just process the game quicker than any other league in the world, so windows of opportunity open and close faster. But he's done a great job adjusting."

The attributes that stand out to Sullivan the most about Marino's game that are allowing him to have success are his skating ability, smarts, size and his strength.

"He's really strong on the puck," Sullivan said. "His mobility is, I think, one of his biggest strengths. He closes on people defensively. He has a real good stick and then he's strong enough in the puck battles to win puck battles. I think he's getting better with every game that he plays."

Marino credits the players around him for helping him feel comfortable.

"I think there's a ton of experience in the locker room and a lot of great support staff here," Marino said. "I think that's helped with the transition a lot. The coaching staff has been great, the players too, really taking me under their wing and showing me the ropes. They've been great about it."

And it's a credit to the veteran group around him for understanding how important that is to a young rookie like Marino.

"He's really only reminded he's a rookie on the rookie dinner night," joked Jack Johnson. "But for the most part, he needs to know he's a big part of the team and we appreciate what he contributes. I think everyone has done a great job of making him feel like he's been part of this. That helps a lot on the ice. But he's earned it. He's played really well. I think he's been feeling more and more comfortable every day."