The unexpected death of St. Louis' mother during these playoffs kept him away from hockey for one day. Moore was out of the NHL for 1 1/2 years after his wife contracted a rare and ultimately fatal illness.
Now they are finding solace on the ice and in the close-knit New York dressing room. The veteran forwards have provided key goals that have fueled the team's surge to the Eastern Conference title.
In the conference finals against Montreal, St. Louis scored in overtime of Game 4 to give the Rangers a 3-1 series lead. Moore netted the only goal Thursday as New York advanced to the Cup finals for the first time in 20 years with a Game 6 victory at raucous Madison Square Garden.
The 38-year-old St. Louis has been counted on to score during his long career. Moore, a grinder, is chipping in from the Rangers' gritty fourth line. Of his three playoff goals, two have been game-winners.
''It's an incredible feeling to be able to play for the Cup,'' the 33-year-old Moore said. ''The opportunity is something special that you look forward to since you're a kid.''
It is a dream that might have seemed lost not long ago.
Moore stepped away from the San Jose Sharks in April 2012 during the playoffs to take care of his wife, Katie, who died in January 2013 from liver cancer at 32.
Moore began his NHL career with the Rangers during the 2003-04 season after playing at Harvard. He had stints with Pittsburgh, Minnesota, Toronto, Buffalo, Florida, Montreal, Tampa Bay and San Jose, before returning to New York last summer on a one-year, $1 million deal.
''It's been a long, pretty amazing journey, so far, and hopefully it continues,'' Moore said. ''I owe a lot to my teammates for helping me get through this last year and a half. I just feel tremendously proud to be a part of this team, especially amid the circumstances of going to the Stanley Cup finals.''
He split the 2011-12 season with Tampa Bay and San Jose, scoring four goals and adding 21 assists in 79 games. Moore's time away didn't dull his skills or his desire. Now he is on the cusp of a championship.
''Every time we've had a big game, he's stepped up with a great performance,'' defenseman Marc Staal said. ''He's a guy that talks about it a lot, too - not being afraid to make mistakes, and going out there and playing confident.''
St. Louis' turmoil was more sudden. He learned of his mother's death when he arrived in Pittsburgh before Game 5 of the second round. The Rangers were already facing playoff elimination after a subpar home loss the night before dropped them into a 3-1 series hole.
St. Louis headed home to the Montreal area to be with his family, but returned to Pittsburgh the next day. The gesture galvanized the club, the players comforting a grieving teammate. The Rangers went on to the best comeback in franchise history.
New York beat Pittsburgh in Game 5, went home for another win on Mother's Day - a game in which St. Louis scored the first goal - and then claimed Game 7 back on the road to advance to the conference finals.
''I know both (Moore) and Marty have gone through some challenging times,'' Rangers coach Alain Vigneault said. ''I think they've found refuge, found a way to find a place where they can be happy. That is at the rink with their teammates and on the ice. They've both been very inspirational leaders throughout the whole thing.''
The Rangers are 7-2 since St. Louis' mother died. The funeral was held outside Montreal between Games 1 and 2 there, allowing the Rangers to attend as a team.
Moore had six goals and 12 assists in 73 regular-season games. He scored twice in the first round against Philadelphia, including the winner in Game 5. He is the Rangers' nominee for the Masterton Trophy, given to the NHL player who best exemplifies perseverance and dedication to hockey.
''There have been quite a few story lines this year, and those two are obviously big ones,'' assistant captain Brad Richards said, referring to Moore and St. Louis. ''That's just the way things go with teams that go through runs. There always seem to be little things that you can grab and build on.
''The stars have to align, and it's great that those guys have the feeling that someone is watching over them and helping them out.''