Flat. Uninspired. Lethargic. Those three adjectives best describe the Bruins’ Game 3 performance against the Lightning.

The only silver lining was Tuukka Rask (33 saves) keeping things close. Now, the Black and Gold trail the best-of-seven series two games to one heading into a pivotal Game 4 Friday night.

“We were slow at times, and stubborn,” a blunt Bruce Cassidy said postgame.

Here is what we learned from the B’s 4-1 loss to the Bolts Wednesday night at TD Garden.

Sloppy puck management carries over into Game 3

ONDREJ PALAT OPENS THE SCORING UP VERY EARLY FOR TAMPA!#GoBolts 1 – 0 #NHLBruins

(Series Tied 1-1) pic.twitter.com/T3QwKMPDME

— Hockey Daily 365 (@HockeyDaily365) May 2, 2018

Putting super glue on the blade of the stick might be the only thing that can help the Bruins possess the puck at this rate.

Boston’s puck mismanagement, if you will, reared its ugly head early when Matt Grzelcyk couldn’t corral a rolling puck, Bill Buckner style. This led to Tyler Johnson feeding Ondrej Palat for his first of two on the evening, giving the Lightning the 1-0 lead just 1:47 in.

“[The] puck kind of felt like it back-spin on me on the ice,” Grzelcyk said about the miscue. “[I] thought maybe it went behind me, so [I] just took my eye off the puck, I guess. And they capitalized because they’re a good team. Obviously not the way you want to start a game. It was tough bouncing back after that.”

Indeed it was.

The Bruins had their moments of extended zone time and quality chances. Their 29 shots on goal marked a series high. But the errant passes and costly turnovers led the Bolts to their third straight 30-plus shot outburst.

That is one area that the Bruins will need to clean up quickly. Otherwise, they’ll be heading to Tampa in a 3-1 series hole.

Marchand frustrated over inconsistent officiating

The disparity in power play chances for the Bolts (five) and Bruins (one) indicates that the officiating played a big part in deciding Game 3. It didn’t. The Bruins’ sloppy puck possession and uninspired play are the two main reasons why they are behind the proverbial 8-ball.

Riley Nash’s first-period interference penalty and Torey Krug bearhugging Brayden Point were legitimate calls. So was Brad Marchand slashing Anton Stralman. Yet Marchand — again — didn’t get the benefit of the doubt, especially after being on the other end of a breakaway attempt that was halted by Stralman’s slash, which didn’t draw a call, back in Game 2.

That led to the three-time 30-goal scorer asking for a little more consistency from the men in stripes.

“It’s just funny how inconsistent they are,” Marchand said. “A slashing penalty is the same that I had on a breakaway last game, was 3-2. A little consistency would be nice.”

What changes are needed for Game 4?

From X’s and O’s to personnel decisions, some changes are indeed needed before Friday night. But the Bruins aren’t hitting the panic button yet.

“It is what it is. We’re down 2-1,” Marchand said. “We’ll bounce back and get ready for the next game.”

Puck management and better starts are two prime goals the Bruins need to accomplish to bounce back and even the series. That might require some lineup tweaks from Cassidy.

One trio, in particular, that needs changing is the third line of Danton Heinen, Riley Nash and David Backes. Nash was the only one of the bunch to notch over 10 minutes of ice time Wednesday night. Their only highlight occurred when Backes tried to inspire his team after his bout with Cedric Paquette. Even then, the ex-Blues captain served seven minutes in penalties — including an extra two for boarding Dan Girardi prior to the fight with Paquette.

Heinen felt the wrath in Game 6 of the Leafs series. He’s the most likely to feel the wrath again if Cassidy makes a tweak to the third line. Who would Cassidy decide to fill that void, though? Ryan Donato — a promising but still unproven prospect with just one game of postseason experience? Brian Gionta — a veteran who gave the B’s a lift on the bottom-six late in the regular season with key players injured? Or Tommy Wingels, who returned to the lineup in place of Tim Schaller in Game 3?

Or does Cassidy keep the faith in the Heinen-Nash-Backes trio?

“Well, that’s a good question,” Cassidy said. “I am concerned, and we always look – we’ve got some guys that weren’t dressed tonight that have played well for this team. So, we’ll have that conversation tomorrow. I think it’s easier to do the next morning than immediately after the game. Some guys have had a tough time…If they stay in, obviously they need to be better.”

So will the other 17 members dressed in Black and Gold come Friday night.