Not long before that, each had played for the Wilkes-Barre/Scranton Penguins, Pittsburgh's affiliate in the American Hockey League.
Dumoulin was there for nearly the entire 2014-15 season before being called up to Pittsburgh and appearing in five playoff games in 2015 before becoming a full-timer in 2015-16.
Murray had arrived on March 1 as injury cover for starting goalie Marc-Andre Fleury. Instead, Murray wrote one of the great Stanley Cup stories, stealing the job and winning 15 playoff games to help Pittsburgh win the Cup for the first time since 2009.
Dumoulin and Murray were not the only baby Penguins involved in that historic night, just the ones front and center.
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Forwards Conor Sheary, Bryan Rust and Tom Kuhnackl each started 2015-16 in Wilkes-Barre but played a major part in the Penguins postseason. Defenseman Derrick Pouliot and forward Oskar Sundqvist each played in two postseason games for Pittsburgh.
That was the Penguins front office's plan all along.
"Our No. 1 goal [with Wilkes-Barre/Scranton], beyond winning, is to develop assets and assets aren't just players," Wilkes-Barre/Scranton CEO Jeff Barrett said Wednesday, standing outside the dressing room at the state-of-the-art practice rink here. "They are hockey operations guys, coaches, front-office people. We develop assets for the Pittsburgh Penguins and in developing assets and doing it in a [winning] environment, it kind of feeds off itself."
Twelve of the 25 players who appeared in the postseason for the 2016 Penguins played in Wilkes-Barre at some point during their careers. The coach, Mike Sullivan, who replaced Mike Johnson on Dec. 12, also started the season with the AHL team.
Each is proof that the road to the Pittsburgh Penguins goes through Wilkes-Barre.
The list of players traveling that road continues to grow. After the postseason success of Wilkes-Barre/Scranton players last season, Pittsburgh has not hesitated to call up players this season, when injuries decimated its roster.
Fourteen players have been called up this season from Wilkes-Barre/Scranton. Eleven of the players on the Penguins' playoff roster have played at least one game in Wilkes-Barre this season.
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Each of them has made that 265-mile ride dreaming that he could be the next to stick around for good in Pittsburgh.
Then there is Zach Aston-Reese, a Hobey Baker Award finalist this season from Northeastern University who arrived in Wilkes-Barre less than a month ago. He signed with the Penguins as a college free agent, drawn, in part, because of the frequency of minor leaguers going to Pittsburgh.
"I've played against some of the guys that have come through the system like Sheary and Rust and [Scott] Wilson, they played [in] Hockey East and I got to see those guys when I first started out at Northeastern and to see how much they have grown as players and contributed to the team's success at the NHL level, that was really attractive," Aston-Reese said Wednesday after a long and intense practice. "I definitely have a lot of work ahead of me but it is not out of reach."
Aston-Reese is already dreaming about his chance to make the trip to Pittsburgh.
"It's a long ride," said Sundqvist, who was up with the Penguins from March 10-29 and called up again for their final game of the regular season Sunday. He played in 10 NHL games. "It's more fun when you are going up than when you are coming back. It feels like it takes forever [coming back]."
Every player knows the opportunity exists to make it a one-way trip. Friends and teammates have shown the way.
"They say every training camp, there's a road from Wheeling to Wilkes-Barre to Pittsburgh," said forward Tom Kostopoulos, the 38-year old captain of Wilkes-Barre/Scranton. "Guys have done it before. They tell us if you work hard, do your job and are a good person, there is a chance for you to move up and a lot of guys have taken advantage of it.
"I've had my shots and now it is my job to help them. When I see that whole group that went up and won the Stanley Cup, it's amazing. Now, I want to see this next level [of players] develop."
Any of the call-ups this season, or another yet to be promoted, could be the next spring sensation for the Penguins, who laid the groundwork for this pipeline more than a decade ago.
Jason Botterill, Pittsburgh's associate general manager and the GM of the "Baby Penguins," says that mindset was born out of necessity. The introduction of the NHL salary cap starting in 2005-06 changed the landscape.
The Penguins realized they were going to have a good deal of money tied to their foundational superstars: forwards Sidney Crosby and Evgeni Malkin, defenseman Kris Letang and Fleury. With that reality, the mandate became to find a way to develop young players on entry-level contracts who could help surround that core and keep the Penguins competitive.
"Finding different avenues, whether it is European players, college free agents or our own draft picks, that is what we are challenging our scouts to do," Botterill said, "and then our development staff [has] to work with and develop these players, whether they are a first-round pick or an undrafted free agent."
After Game 6, at the Penguins' celebration in San Jose, Barrett sat in a corner with Sullivan and Botterill. They were savoring what had just happened.
"The whole team was celebrating and we look over and all the Wilkes-Barre guys are celebrating together with their wives and families," said Barrett, who has been with Wilkes-Barre/Scranton since its inception in 1998. "It was a pretty neat scene."
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It was also validation of the philosophy Botterill and Barrett share for the two organizations. Pittsburgh wants to develop assets in the AHL, and Wilkes-Barre/Scranton wants to win at that level.
It is a hard line to walk in the AHL. Some teams are good at developing young players, but struggle on the ice. Others win consistently, often relying on veteran players, but don't produce a steady flow of prospects to the parent club.
This season, the Pittsburgh Penguins are going to the postseason for the 11th straight season. The Baby Penguins have qualified for the AHL playoffs for 15 straight seasons.
"I think Pittsburgh has made a conscious investment in Wilkes-Barre and then they have the right mixture in the importance on developing and competing in this league," said Kostopolous, who has played parts of 10 seasons with Wilkes-Barre Scranton. "Developing and winning go hand and hand. I feel some teams in the AHL just want to develop and some teams just want to win and this organization has done a good job in finding the right balance where we want to win but develop in the process."
That was on full display with the 2016 Stanley Cup champions.
"I think it was a scenario where they were just feeding off each other, they supported each other," Botterill said, "and it was a big reason why there was that group of players having that success story last year."