Whether perched behind the bench clutching a paper cup of black coffee or tutoring 7-year-old skaters in the art of on-ice tag, Martin St. Louis approaches his new role with the same intensity that won him two NHL scoring titles and a Stanley Cup.

More than four months after ending a 16-season NHL career that will almost certainly land him in the Hall of Fame, St. Louis has seamlessly transformed into a full-time father and coach for his sons, Ryan, Lucas and Mason.

St. Louis runs weekday practices, coaches games on weekends and travels with the Mid Fairfield Junior Rangers teams.

“I love hockey; I need it in my life,” he said after four hours of nonstop ice action on a recent Saturday afternoon at the Chelsea Piers complex here. “I want to teach, but more importantly, I want these kids to build good human qualities through sports.”

The self-effacing St. Louis, 40, built his career on hard work and an attitude that he could outwill the competition. An undrafted 5-foot-8 right wing out of the University of Vermont, he amassed 1,033 regular-season points, including 391 goals, with Calgary, Tampa Bay and the New York Rangers.

He won a Stanley Cup with the Lightning in 2004, was a six-time All-Star and twice played for Canada in the Olympics.

“He’s very intense,” said his wife, Heather, who met him in college during the summer of 1996. “He’s taken all that energy and now focuses it on the kids. He’s a real student of the game.”

St. Louis helps run spirited drills for the Mite Minor group of 7-year-olds, including Mason. On that afternoon, St. Louis, wearing a Rangers toque and sweatshirt and with a whistle dangling from his neck, animatedly conducted a drill of tag, with two skaters alternately chasing around a barrier between them.

Exhibiting the same quick starts and stops that had made him so elusive on the ice, St. Louis demonstrated proper positioning and periodically stopped the diminutive players to offer encouragement.

He playfully tugged their sweaters to maneuver them into correct position for the next drill and laughed with them as they often slipped and tumbled to the ice.

“They are so young, they probably don’t know who I am and what I did, and that’s fine,” St. Louis said. “It’s about repetition and developing good habits and skills.”

After practice for the youngest group, there were two games — 10-year-old Lucas’ Squirt Major group against a team from Morristown, New Jersey, and 12-year-old Ryan’s Pee Wee Major team versus an opponent from Washington.

“It’s about teaching the kids to be good teammates and to be coachable,” St. Louis said. “I want them to learn that it’s about ‘How do I help the team?’ not ‘How does the team help me?’”

St. Louis likes to stand as high as he can behind the bench, talking to the youngsters as they leave the ice and offering advice before their next shifts. He said he treated every child on the ice as his own.

His three sons wear their father’s No. 26, and the older two shoot left-handed, as St. Louis did.

“That’s the number they want,” said St. Louis, whose childhood idol, Mats Naslund, wore No. 26 for the Montreal Canadiens. “I asked them all: ‘Are you sure? You can have another.’ Right now, they all like it.”

A longtime resident of Greenwich, Conn., St. Louis asked for a trade to the Rangers during the 2013-14 season. After arriving in March, he was a key part of the team’s run to the Stanley Cup finals.

The dedication and focus St. Louis bring to his latest endeavor do not surprise former Rangers teammates.

“Marty was always watching his sons’ games on his phone when we were on the road,” goaltender Henrik Lundqvist said. “He was so into it — watching the kids as much as playing himself.”

Rangers center Derick Brassard said St. Louis’s jovial presence was missed this season.

“His humor and his leadership were fun for all of us,” said Brassard, a fellow French Canadian who is 12 years younger than St. Louis. “We miss Marty in the room, but I’m really happy he’s enjoying life with his kids now.”

For parents whose children are part of the Stamford hockey scene, St. Louis is a valued addition, but he is treated like any other father on school days.

“I always yell at him to keep the line moving during the car pool,” said Samantha Cleaves, whose son Hank plays on the Pee Wee Major team coached by St. Louis. “But in all seriousness, Marty has been fabulous. He’s special to all of us because of the person he is.”

Nelson Peltz, chief executive and founding partner of Trian Fund Management, whose twin sons, Zach and Greg, are teammates of Ryan St. Louis’, also appreciates having a former Ranger on board full time.

“Marty is very disciplined; he’s all in,” Peltz said. “It’s a pleasure to have him on the bench. And the kids get to learn from a Hall of Famer.”

Heather St. Louis is happy for new routines after years of juggling hockey schedules with school and everyday life.

“It’s been a game changer for all of us,” she said. “Our family is together, and the boys are happy their dad is around for them every day.”

Mulling his favorite aspect of life away from grueling summer workouts and the rigorous NHL season, St. Louis paused before answering.

“It would have to be loading up the car with all the hockey stuff and going with my three boys to the rink,” he said. “I’m at my happiest when we are on our way and talking hockey.”

Asked the same question after hearing her husband’s answer, Heather laughed and replied without hesitation.

“Mine, too,” she said.