PRINCE.EDWARD.ISLAND (CBC) - If the NHL wanted the battle of all battles in this year's Stanley Cup playoffs, it might have hit the jackpot with the much-anticipated Eastern Conference final featuring the Pittsburgh Penguins and Philadelphia Flyers.

The Pennsylvania rivals don't care for each other too much, perhaps since they were expansion siblings in 1967.

"There's a hatred between the two teams, and, if you want to get somewhere, you have to go through each other to get there. That's just how it is," Flyers forward R.J. Umberger told reporters on the eve of Friday's series opener in Pittsburgh (CBC, CBCSports.ca, 7:30 p.m. ET).

Some NHL rivalries evolve from a big game, a major trade or a short-lived scuffle, then fade after a few years.

Not the Philadelphia Flyers versus the Pittsburgh Penguins.

This rivalry is real, perpetual and mostly downright nasty.

Remember Sidney Crosby's rookie season with the Penguins in 2005-06? It included an impressive 102 points by the Cole Harbour, N.S., native but also a nasty confrontation with Philadelphia defenceman Derian Hatcher.

Crosby was bloodied by a Hatcher high-stick and lost three teeth, but didn't draw a penalty. He later got his revenge, scoring the winning goal in overtime, as allegations of diving were made.

"I think Sid's come a long way," Hatcher said of Pittsburgh's captain this week. "I think he's learned to play through a lot of that [physical] stuff, just by watching him a little bit in the playoffs. But we'll see."

And there it is: Hatcher setting the stage for another physical battle. The survivor will play for a Stanley Cup championship.

The Flyers haven't won the Cup since the days of Bernie Parent in 1975, while the Penguins last hoisted Lord Stanley's mug in '92 after sweeping the Chicago Blackhawks.

Philadelphia holds the edge in head-to-head meetings with a 129-76-31 record, including victories in all three playoff series between the teams.

This season, the Flyers took five of the eight matchups as the teams combined for a remarkable 86 power plays and 20 power-play goals.

Philadelphia dropped its third straight at Mellon Arena on April 2, taking six penalties and watching the Penguins score four power-play goals in a 4-2 victory.

After the game, Pittsburgh coach Michel Therrien said his players "punished" the Flyers for "their lack of discipline." Philadelphia coach John Stevens didn't comment when told of Therrien's comments.

Their history dates back to the American Hockey League, where Stevens beat Therrien twice in the playoffs, most notably in 2005 when the Philadelphia Phantoms downed the Wilkes-Barre/Scranton Penguins for the Calder Cup championship and the two coaches exchanged words behind the bench.

"This [series] isn't about me or him," Stevens said. "This is the Flyers versus the Penguins with a lot of great players and stories on both teams."

Added Therrien: "It's always been a good hard-nosed series every time we've faced each other in the playoffs ... he's a good coach."

Fortunately for Therrien, his players won't have to face Kimmo Timonen, the Flyers' most skilled defenceman, who was expected to be matched against scoring star Evgeni Malkin.

He is expected to miss the series with a blood clot in his left ankle that developed during the conference semifinals against the Montreal Canadiens.

"We have to view this that he is not a player for us in the series and march on," Flyers general manager Paul Holmgren said.

Pittsburgh has won eight of nine in this year's playoffs and all five home games - a relatively easy start for a youthful team whose three biggest stars, including goalie Marc-Andre Fleury, are 23 years old or younger.

But they'll probably have to find a way to stop Umberger, a Pittsburgh native who scored eight goals in Round 2 against Montreal.

And the Flyers' No. 1 challenge? Containing the multiple waves of scoring chances that will emerge from the Malkin and Crosby lines.

"We know they will target guys like Crosby and Malkin and [Marian] Hossa and [Petr] Sykora, but that is fine," Therrien said. "That is the playoffs.

"Ottawa tried to do it [in the East quarterfinals]. The [New York] Rangers tried to do it [in the semifinals]."

And the Penguins survived.

Bring on the Battle of Pennsylvania.

With files from the Associated Press

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