5 Keys: Lightning at Bruins, Game 4

LIGHTNING at BRUINS
7 p.m. ET; NBCSN, CBC, TVAS
Tampa Bay leads best-of-7 series 2-1
The Boston Bruins will try to get even with the Tampa Bay Lightning in Game 4 of the Eastern Conference Second Round at TD Garden on Friday.

Bruins forwards Brad Marchand and Jake DeBrusk are considered game-time decisions because of injuries. Neither practiced Thursday, but DeBrusk skated Friday morning.
"I believe both Marchand] and Jake will play, but if not there's a domino effect," Bruins coach Bruce Cassidy said.
***[RELATED: [Donato returns to lineup for Bruins for Game 4 | Complete Lightning vs. Bruins series coverage]*
The Lightning have won the past two games, including 4-1 in Game 3 on Wednesday, after a 6-2 loss at home in the series opener. Tampa Bay is 6-3 all time in Stanley Cup Playoff series when holding a 2-1 lead and has extended the series lead to 3-1 on three straight occasions.
Here are 5 keys for Game 4:

1. Lightning can't settle for split

Lightning coach Jon Cooper looks at Game 4s in the other three second-round series as cautionary tales.
The Winnipeg Jets, Vegas Golden Knights and Washington Capitals had 2-1 leads after three games. Each lost Game 4 because their opponents either executed better, had a higher desperation level, or both.
The Lightning don't want to fall into the same trap after outplaying the Bruins in Games 2 and 3 and regaining the home-ice advantage by winning in Boston.
"We can't exhale," Cooper said. "Do you want to make it a best two out of three or do you want to make it to where now we get three chances to knock them out? … When you have this chance, you don't want to let it slide."

2. Bruins need more power plays

The Bruins have had five power plays in this series, scoring twice. Their power play was a weapon during the regular season, ranking fourth at 23.5 percent, and they are first during the playoffs (34.6 percent; 9-for-26). However, they need more opportunities.
"But part of that's on us to have more urgency around our net so that you're in a position to draw penalties, right?" Cassidy said. "That's kind of how it works."

3. Boston must stay disciplined

On the other side, Tampa Bay has had 12 power plays this series (scoring three times). In Game 3, the Bruins gave the Lightning five power plays, and Marchand got a 10-minute misconduct in the final minute of the third period.
The Bruins feel an early lead will help them maintain their discipline.
"When you're chasing it all night, that obviously will put you on your heels and you're going to take penalties when you're trying to take the puck away," forward Riley Nash said. "So, I think [it's about us] just possessing [the puck] more."

4. Lightning need more from Stamkos line

The Lightning's top line of Steven Stamkos, Nikita Kucherov and J.T. Miller has been limited to two points in the series. Both came on Stamkos' empty-net goal power-play goal at the end of Game 3 (Miller had an assist).
Tampa Bay has gotten 26 points (nine goals, 17 assists) from its other three lines and six defensemen to have a 2-1 lead in the series. That said, it seems impractical to think the Lightning can win the series without getting anything from its top line.
"The good thing is we're up in the series and we feel we have a lot more to give as a line, which is definitely a positive," Stamkos said.

5. Donato factor

Although Cassidy wouldn't commit to a definite lineup because of questions about Marchand and DeBrusk, he announced rookie forward Ryan Donato will play.
Donato had nine points (five goals, four assists) in 12 games in the regular season after signing with the Bruins following the end of his college season with Harvard. He had no points in Game 2 against the Toronto Maple Leafs in the first round and has been scratched for the past eight games.
The Bruins are inserting him because they think he can add speed and an offensive threat.

Lightning projected lineup

J.T. Miller -- Steven Stamkos -- Nikita Kucherov
Ondrej Palat -- Brayden Point -- Tyler Johnson
Alex Killorn -- Anthony Cirelli -- Yanni Gourde
Chris Kunitz -- Cedric Paquette -- Ryan Callahan
Victor Hedman -- Dan Girardi
Ryan McDonagh -- Anton Stralman
Braydon Coburn -- Mikhail Sergachev
Andrei Vasilevskiy
Louis Domingue
Scratched:Andrej Sustr, Jake Dotchin, Slater Koekkoek, Cory Conacher, Peter Budaj
Injured:Adam Erne (lower body)

Bruins projected lineup

Brad Marchand -- Patrice Bergeron -- David Pastrnak
Jake DeBrusk -- David Krejci -- Rick Nash
Ryan Donato -- Riley Nash -- David Backes
Tim Schaller -- Sean Kuraly - Noel Acciari
Zdeno Chara -- Charlie McAvoy
Torey Krug -- Kevan Miller
Matt Grzelcyk -- Adam McQuaid
Tuukka Rask
Anton Khudobin
Scratched:Tommy Wingels, Danton Heinen, Brian Gionta, Nick Holden, Dan Vladar](https://www.nhl.com/player/dan-vladar-8478435)
Injured:None

Status report

Palat didn't practice Thursday but is expected to play. … Cassidy said it's not clear who Donato will replace.
NHL.com correspondent Matt Kalman contributed to this report