The comeback, if there is to be one for the Pittsburgh Penguins, starts Friday night (8 p.m. ET, NBCSN, CBC, RDS) at TD Garden in Game 4 of the Eastern Conference Final.

The Penguins trail the Boston Bruins three games to none in the best-of-7 series that determines who represents the Eastern Conference in the Stanley Cup Final.

The odds are extremely long -- only three teams in the history of hockey have done it -- and the work required will be arduous.

It can be done, though. In fact, the Philadelphia Flyers did it to these same Boston Bruins three years ago.

The Bruins have coughed up a 3-0 series in the recent past and almost coughed up a 3-1 lead in the first round this spring against the Toronto Maple Leafs. But the Penguins see little solace in that recent history.

"As far as numbers and odds and everything like that, every year is different," Pittsburgh winger Pascal Dupuis said. "If you ask them, they were up 3-0 a couple years ago, and they lost. So it's numbers, different players, everything is different about this one."

That means that Pittsburgh will have to make its own history here in this Eastern Conference Final. If they do, they will join the hallowed company that has faced sport's longest odds and refused to blink. If they falter, they will start their summer earlier than anticipated.

Here, then, is a five-step plan for Pittsburgh to extend this series to a game 5 on home ice, which can be the team's only goal at this point.