The letters across the blue-and-white sweater read MAINE, but that merely reveals where the widely dispersed players in a tradition-rich hockey program pick up their mail.

Twenty-five players will represent the Black Bears at this week’s NCAA Frozen Four in St. Louis. Five grew up in the Canadian province of Ontario. Three hail from Massachusetts, another three from British Columbia. Minnesota, Quebec and Saskatchewan each produced two Maine skaters.

Matt Duffy is the only one who grew up with “The Maine Stein Song” ringing in his ears before he knew what a stein was or reached the age when it was OK to hoist one.

Local fans were spoiled by the recent St. Dominic Regional High School tandem of Greg Moore and Derek Damon, but Maine only sporadically spawns Division I hockey talent. The state university has won hundreds of games over the years without a native on the ice. This season, there are as many players (one) from Florida, California, Missouri and Newfoundland on the roster.

That’s a double-edged sword for the 21-year-old Duffy, a 6-foot-2, 200-pound sophomore defenseman from Windham. He knows he’s a hometown hero. He also knows he’s being watched by fans, young and old, who might live vicariously through him.

“It’s a little bit of both. There’s pressure in being the Maine kid because people expect more of you,” Duffy said. “But every time you put on this jersey, it’s a blessing to be representing your home state.”

Hockey playoff games are won with coaches preaching the mantra that football made famous: Defense and special teams. Duffy could play a pivotal role in both areas when No. 6 Maine (23-14-2) meets No. 5 Michigan State (24-13-3) at 4 p.m. Thursday (ESPN2) in the national semifinals.

Duffy scored five goals this season, all on the power play, coupled with five assists. He also emerged as an enforcer on a young, patchwork defense that performed splendidly in front of sophomore goaltender Ben Bishop during the NCAA East Regional.

“I don’t score many goals,” said Duffy, “but I think I’ve scored a lot of pretty big goals.”

That trend took hold at the end of Duffy’s freshman campaign. Duffy delivered all three of his first-year goals during Maine’s post-season push to the Frozen Four. He lit the lamp twice in the Hockey East quarterfinal series against UMass-Lowell, including a game-winner.

Duffy backed that up with a goal and an assist in the East Regional final against Michigan State, putting himself on the All-Tournament team. He also registered an assist in a semifinal loss to Wisconsin.

This year’s exploits with the man advantage include a Feb. 3 game-winner at New Hampshire and a March 24 insurance tally against Massachusetts to clinch another East Regional crown. Duffy has five of Maine’s 58 power-play strikes, while the Black Bears yielded only 28 to its opposition.

“Our power play is first in the country right now,” said Maine senior Josh Soares. “That’s a huge key to our success. It’s not like other teams that have only five to seven guys with one guy staying on for the full two minutes.”

He’s one component in a talented machine right now, but Duffy was a shooting star throughout his formative hockey years.

After a stellar career at Cheverus High School in Portland, Duffy spent two years with the New Hampshire Junior Monarchs, scoring 66 points in 87 games.

“It was a lifelong dream to play (in Orono),” said Duffy. “I actually got a letter when I was about 14, saying, ‘Keep up the good work, and maybe we’ll see you up here someday.'”

No matter how far away from home, getting to the Alfond Arena ice and staying there are two different accomplishments. Duffy said that the Division I game is faster and more physical than juniors.

Then there’s the in-house competition. Duffy started the season on the Maine power play before seeing decreased action there in February and March.

When Keenan Hopson underwent an appendectomy the Tuesday before the East Regional, Duffy was back in the rotation. Four nights later, he was a central figure in helping the Black Bears avenge four straight losses to UMass and reach their fourth Frozen Four in six seasons.

“They put me back there, and I just tried to contribute as much as I could,” Duffy said. “The goal every year is to get to the NCAA Frozen Four. You just want to help get that trophy and try to develop as a player, person and teammate.”