Up 3-1 in their series against the Senators after a 7-3 beat down in Ottawa Wednesday night, the Penguins appear to be on their way to an Eastern Conference Final showdown with the Boston Bruins.

The team is beginning to fire on all cylinders, and if not for a defensive breakdown in the last minute of game three, the Penguins would have swept the Senators out of the postseason.

All this being said, there is still one aspect of Pittsburgh’s game that must improve for them to hoist Lord Stanley’s Cup come the end of June.

It doesn’t matter who starts in goal, whether it’s Tomas Vokoun or Marc Andre Fleury. To become champions of the NHL, the Pittsburgh Penguins must be more responsible defensively in front of their own net.

When the New York Islanders beat the Penguins 6-4 in game four of the first round, Coach Bylsma wasted little time announcing that Tomas Vokoun would be between the pipes in game five. This was not only a message to Marc Andre Fleury, but to the rest of the Penguins roster as well, especially the defense.

When a coach makes the decision to change goaltenders, it takes away a teams comfort level. Teams don’t have as much trust in a backup goalie as they would in someone like Fleury, who is not only loved by his teammates, but also has a resume that includes a Stanley Cup and a gold medal.

In Vokoun’s first five starts, the Penguins played like an uncomfortable team. They made defense a priority and let the goals come, as they will when you have a roster with that much offensive firepower.

However, in Vokoun’s sixth start, which was game four on Wednesday night, the Penguins started to return to some of their old habits and drift back into their comfort zone.

Even though the Penguins won lopsidedly, mistakes were made that could have or would have cost them the game against a better team. The Penguins trailed 2-1 after the first period, and both goals were do to a lack of defensive responsibility. Evgeni Malkin and Kris Letang failed to get back in their zone allowing the Senators to score their second shorthanded goal of the series, and giving Ottawa all the momentum in the process.

Even when the Penguins captured that momentum back on a signature James Neal wrist shot to tie the game at one, another defensive gaff gave Ottawa the lead back less than two minutes later. Letang played soft defense in front of Vokoun and Matt Niskanen missed his assignment, allowing Kyle Turris to bury a rebound right into the Penguins open net.

Fortunately, these two defensive breakdowns didn’t cost the Penguins, as they responded and cruised to a 7-3 win. However, against a better team like the Boston Bruins or any of the remaining four teams in the Western Conference, mistakes like this could cost the Penguins a game, and ultimately a series.

There is no denying the Penguins have the offensive talent to light up the scoreboard, but in the Stanley Cup playoffs a championship isn’t won by offensive firepower. To win a championship you must keep the other team off the scoreboard, and that starts with defensive responsibility.

Regardless of who is in the net for the Pittsburgh Penguins, if they make defense the first priority and allow the goals to come, there is little doubt in my mind that no opponent can prevent this group from having their names etched onto the Stanley Cup.