Captain for captain. The face of the Lightning franchise - unhappy as he was at the time - for a homegrown, hard-working blue collar guy the Rangers were not going to be able to re-sign.
For the Rangers, it was the last piece of the puzzle in getting them to the Stanley Cup Finals. St. Louis probably provided more of an emotional lift than a scoring one with his ability to rally after his mother's death in the second round.
A year later, St. Louis and Callahan are again focal points, this time as the Rangers and Lightning meet in Game 1 of the best-of-seven Eastern Conference finals Saturday afternoon at Madison Square Garden.
Coming in, both carry question marks. Callahan has yet to score a goal in the postseason and had an appendectomy earlier this week. St. Louis not only hasn't scored in the playoffs, Rangers coach Alain Vigneault benched him in the third period of Game 7 against Washington on Wednesday.
"Of course coaches make decisions at key times in the game for whatever reason," St. Louis said Friday after practice . "I've never liked being left on the bench at certain times, but that's just reality. If I liked it, I don't think I would be here today. Nobody likes that.
"But right now I'm focusing on Game 1 and helping my team win. I'm not too worried about what happened toward the end of that game. I trust AV's judgment."
St. Louis has had chances, but has been unable to bury the puck. It's won't get any easier against the Lightning and goaltender Ben Bishop, who has not lost to the Rangers in eight games.
Bishop has a 1.81 goals-against average in 13 playoff games.
That St. Louis is struggling going into a series when people will focus on him adds more pressure.
"Like I said, I've got a lot of close friends, but this is playoff hockey," said St. Louis, who will turn 40 next month. "We've got the rest of our lives to be friends. This is right now a team that's in our way of getting where we want to be."
"He is working real hard," Vigneault said. "That line has had some good looks. Defensively, they have been very responsible. Obviously, when you are talking about Marty St. Louis, Rick Nash and Derick Brassard, you are thinking of three strong offensive players. Can we get a little more out of them? I think we need a little more out of our whole group.
"It's a race to four and we need everybody stepping up their game. Marty is no different."
Callahan practiced without limitations Friday; his status is listed as day to day.
"I was told the recovery period is pretty quick, so ... each day seems to be getting better and better," Callahan said. "I'm going in the right direction."
Lightning coach Jon Cooper said whether Callahan plays may depend on his tolerance for pain.
"Those things are painful (according to) anyone who's ever had one," Cooper said. "But he's a pretty tough kid. So I would suspect he would come back."
Some things to watch in this series:
MAC and G: The Rangers shut down Pittsburgh's Sidney Crosby and Evgeni Malkin in the first round, and limited Washington's Alexander Ovechkin and Nicklas Backstrom in the second. The job of stopping the top lines has fallen to defensemen Dan Girardi and Ryan McDonagh.
Will they will go against the kid line of Tyler Johnson centering Ondrej Palat and Nikita Kucherov, or face up against Steven Stamkos, Alex Killorn and Callahan, if he's in the lineup? Johnson (8), Kucherov (5) and Palat (3) have combined for 16 goals in the postseason.
DIFFERENT TEAM: The Lightning are in the conference finals for the first time since 2011. Just two players, Stamkos and defenseman Victor Hedman, remain on the roster from then. Tampa Bay also made it in 2004 en route to winning the franchise's only Stanley Cup championship.
GOALTENDERS: Henrik Lundqvist of the Rangers has a 1.60 goals-against average and a .944 save percentage in 12 playoff games. Bishop has a 1.81 GAA and .937 save percentage in 13 playoffs games. Don't expect many goals.
REGULAR SEASON: The Lightning won all three regular-season games against the Rangers by a combined 15-7 margin. Here's the catch: The last game was played on Dec. 1. The Rangers got in gear a week later, winning 13 of 14, and posted the best record in the league.
"I think we played them three times in 15 days," Cooper said. "And we were kind of rolling at the time. Those are three more wins that got us to the playoffs. It's much like the five wins against Montreal. We needed those wins to get into the playoffs. When you get to the playoffs, it's a whole different beast."
ODDS AND ENDS: Rangers LW Tanner Glass (maintenance) did not practice Friday, but is expected to play. ... Rangers D Dan Boyle practiced despite feeling woozy after a big hit in Game 7 vs. Washington. ... Rangers RW Mats Zuccarello has not started skating. He missed the last series after being hit in the face by shot by Rangers captain McDonagh. ... Lightning C Valtteri Filppula skated with Stamkos and Killorn in practice.
AP Sports Writer Fred Goodall and freelancer Denis Gorman in New York contributed to this report.