For the fifth time over the past decade, the Ottawa Senators and Pittsburgh Penguins will meet in the Stanley Cup Playoffs.

The two clubs have played three first-round series and another second-round series in that span, with Pittsburgh holding a 3-1 advantage.

But that's all in the past. What lies ahead is a best-of-seven affair, with the winner earning the right to advance to the final.

Here are three storylines to watch:

Battle of the Masterton nominees

This series will feature two goalies nominated for the Masterton Trophy, awarded to "the player who best exemplifies the qualities of perseverance, sportsmanship, and dedication to hockey."

In one crease is Craig Anderson, whose life was turned upside down this season due to a cancer battle fought by his wife, prompting him to take several leaves of absence. When he was able to take to the ice, he played some of the best hockey of his career, and while his numbers have dipped a bit in the playoffs, he remains one of the league's more underrated netminders.

In the other is Marc-Andre Fleury, whose days as Pittsburgh's starting goalie appeared to have come to an end this time last year, when Matt Murray was embarking on a successful run to the Cup as a rookie. It's Fleury who's filling in for an injured Murray this time around, and although this postseason could very well be it for Fleury in Pittsburgh, his renaissance is as big a reason as any for the Penguins' win over the Washington Capitals.

Here's how their playoff numbers stack up:

The slash

It was one of the more gruesome incidents of the regular season, and it could carry into the postseason thanks to this rather unexpected matchup.

The date was March 23, and the principal characters were Sidney Crosby and Marc Methot. Near the end of the opening frame, the Penguins captain caught the Senators defenseman with a slash that quite simply destroyed Methot's finger.

Crosby contended he was aiming for Methot's stick and the NHL didn't give the play a second look, while Methot didn't play again until Game 2 of Ottawa's first-round series against the Boston Bruins more than three weeks later.

On top of that, Senators owner Eugene Melnyk called Crosby a "whiner beyond belief" and argued for a season-long suspension, while the Penguin retorted by saying Melnyk just likes to hear himself talk.

And let's not forget Melnyk once commissioned a forensic investigation into an Achilles injury suffered by Erik Karlsson at the hands of former Penguins forward Matt Cooke.

There's clearly a weird relationship between these two clubs, with the Eastern Conference Final serving as a big stage for grievances new and old to be aired.

Karlsson's conquest

For those who needed a refresher on just how good of a player Karlsson is, this postseason has provided a crash course, albeit unnecessarily.

Not only does Karlsson lead the Senators with 13 points in 12 games (two goals, 11 assists), he ranks first among all remaining defensemen with a Corsi For rating of 57.14 in five-on-five play, meaning he's regularly on the ice for more shot attempts for than against. He also boasts a rating of plus-eight, for the more traditional crowd.

What's even crazier is he admitted to being hindered by a pair of hairline fractures in his left heel earlier in the playoffs. That's remarkable considering he's averaging almost 29 minutes of ice time, and regularly looks like one of the world's best players, scoring and setting up plays in jaw-dropping fashion.

The Senators wouldn't be here without Karlsson, and they won't advance unless he keeps it up, at the very least. If he does, they can go ahead and throw his name on the Conn Smythe Trophy.

Series Schedule

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(Photos courtesy: Action Images)

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