It might be too simple to say that when the going gets tough, the tough get going.

Tough might be too kind a word for the way the Stanley Cup Finals have gone for Boston's top line of Patrice Bergeron, Brad Marchand and David Pastrnak through two games. It's a trio that's universally respected as one of the top handful of lines in hockey -- and if they're going to live up to that billing on the game's biggest stage, Game 3 Saturday night in St. Louis would be a good time to get going.

Will it actually be more difficult for the B's on the road at the Enterprise Center? In the TD Garden split, coach Bruce Cassidy dictated which Blues skated against the Bergeron line. He admitted in Game 1 to trying to get the unit away from St. Louis centerman Brayden Schenn's line, something that would've been unheard of going into the series.

With Blues coach Craig Berube able to decide that the Schenn line, along with Vladimir Tarasenko and Jaden Schwartz, plays against Bergeron's line, is it possible for the Bruins top unit to get going? They combined for 260 regular season points, so its time for them to flip the script: Own the puck, spend the bulk of their time in the offensive zone and force Berube to think about getting his top line away from the presumed Selke Trophy winner wearing No. 37.

"Obviously we have to respond from (Game 2)," said Bergeron. "They're a really good line. They play well together, good at forechecking, turning pucks over. We need to capitalize. For us, it's about being better. We know how we can play. It's about taking care of the puck in our zone."

Tarasenko had goals in both Finals games in Boston and is riding the second longest playoff point streak in Blues history. Schenn had eight hits in Game 2, more than the entire Bergeron line combined. Schwartz, the playoffs leading goal scorer going into the Finals, hasn't done much yet and will be looking to get involved on home ice. So maybe getting back to the shutdown roots of Bergeron and Marchand will help this line get on the right path.

"The whole playoffs, when they're not scoring, they've played against (Toronto's) Tavares and Marner, (Columbus') Panarin and Atkinson, (Carolina's) Williams and Stall and kept them off the scoresheet. They've been able to do that part of the job," Cassidy said. "So far this series, Schenn's line had some five-on-five goals. If they go to that matchup in St. Louis, that's a big challenge for Bergy, March and Pasta."

The 5-on-5 play seems like the best place for Bergeron and Marchand (who hasn't scored an even strength Finals goal since Game 7 against Vancouver in 2011) to find their games. The Garden crowd was delighted when St. Louis was whistled for ten minor penalties in the first two games, but all that special teams ice time seemed to seep into Boston's game in terms of puck sloppiness and fatigue. Credit the Blues' penalty kill, especially center Ryan O'Relly's ability to win faceoffs and clear the puck down the ice, for some of that.

"When you win some draws and send it down it makes life easier," O'Reilly said. "They have elite personnel out there. They work well all together, the way they move the puck. There's so many threats we have to be on them. We have to be as quick as possible. If we're not working, get tired out there, they're going to make us pay."

Only cashing in for two goals in ten chances on the man advantage contributed to the B's leaving Beantown with a split. The 5-on-5 ice time for Bergeron and Marchand was down considerably from their averages in the regular season and given that they're two of the best 5-on-5 players in the NHL, it stands to reason that more even strength time in Game 3 will play in their favor.

"It's about what's in front of you," Bergeron said. "Whatever is behind is in the past. You have no control over it. You just have to go out there and play your style, worry about what you can really control."

Faceoffs were a big issue in Game 2. Bergeron lost eight of his 13 draws, a rarity for a guy considered one of the best draw men in the world. O'Reilly, who won over 1,000 in the regular season and has a 56 percent win-rate, is one of Bergeron's few peers in the faceoff department -- so even if the Bergeron line gets O'Reilly's unit and not Schenn's, it's not necessarily a rosy outlook.

It's not all on the Black-and-Gold's top trio. David Krejci and Jake DeBrusk haven't exactly set the world on fire in two Finals games, either. One of Boston's top two lines has to win their matchup if they plan to win the Cup.

Cassidy pointed out that two games is a short sample size and he's right. Two games of minus-play and no five-on-five production is a blip on the radar for these guys. For the Bruins to come back to Boston still even in the Cup Finals, or ahead, Bergeron, Marchand and Pastrnak need to remind us just how good they are.

"I suspect in Game 3 we'll see their best game of the series," Cassidy said. 

You can contact Matt Williams at MWilliams@gloucestertimes.com and follow on Twitter @MattWilliams_SN.