By Michael Hurley, CBS Boston

BOSTON (CBS) — After a 4-1 loss in Game 3 on Wednesday night, Bruins head coach Bruce Cassidy admitted that his team appeared to be slower than Tampa Bay to that point in the series. He also said his team needed to better defend its own net, and that he’d consider making some lineup changes.

So for Game 4, Cassidy to decided to insert rookie forward Ryan Donato … as well as veteran forward Brian Gionta.

The former was to be expected; Donato was somewhat of a sensation when he debuted with nine points in 12 games at the end of the regular season. But the latter? The latter was a head-scratcher.

For one, after signing with the Bruins in late February and debuting on March 1, the 39-year-old Gionta registered just seven points (2-5-7) in his 20 games played. Gionta ended his season with a stretch of zero goals and just one assist in his final 15 games — a stretch during which he was on the ice for nearly 200 minutes.

So as far as adding scoring to the lineup in place of the lackluster postseason performances of Riley Nash or Danton Heinen, Gionta did not fit the bill as a prime candidate. Gionta also hadn’t played in a game since April 8, allowing a full month of rust to gather on what’s left of his offensive game.

Secondly, after the Game 3 loss, Cassidy expressed an importance for his team to better defend its net. At 5-foot-7, Gionta has never really possessed the physical ability to move bodies, and his lack of speed wouldn’t help Boston defend for any Tampa rushes into the Boston zone.

Nevertheless, Gionta started the game on the third line, centered by Sean Kuraly (moving up from the fourth line) and with Donato on the left wing. The line didn’t make much of an impact in regulation, while Gionta himself didn’t register a shot on net while blocking one shot, registering one hit, and committing one giveaway.

But Cassidy felt enough confidence to send Gionta and Donato over the boards with Noel Acciari in overtime. Sure enough, it was Gionta standing at the edge of the crease as Alex Killorn sent a backhand pass toward the net. Lightning defenseman Dan Girardi casually shoved Gionta out of the way. The puck then nicked off Gionta’s skate before Girardi got his stick on it to redirect the puck off Tuukka Rask’s stick and into the net.

Game over, and for the Bruins, possibly season over.

Girardi scores the OT winner. pic.twitter.com/tOg2rPnUiA — NHL GIFs (@NHLGIFs) May 5, 2018

Now trailing 3-1 in the series and facing elimination in Sunday’s Game 5, Cassidy’s decision to not only insert Gionta into the lineup but to play him in overtime looms awfully large. The coach, though, expressed no regret after the loss.

“We certainly weren’t,” Cassidy said when asked if he considered shortening the bench in overtime. “Not really. I mean, you have to play, and at some point, you’ll look at that. Long change, it’s going to be difficult early, then you lose your matchup. They’re playing four lines, you’ve got to – I mean, the goal that was scored by the line that was on the ice for Tampa, I don’t know if they had a shot on net [all game], so I think the matchup – we were fine there. They won a puck and we didn’t.”

Cassidy said he felt comfortable with the defensive work that Gionta’s line did all game, so the trust was there in overtime.

“We were going to play the guys and trust them to do their job, and if someone wasn’t [playing well] as it went along or there was some fatigue, we would have looked at it,” Cassidy said.

As for the winning goal allowed, Cassidy attributed it to a “fortunate bounce.”

“[Donato and Gionta] were on the ice for the goal against at the end, so that never looks good. But, by the same token, it wasn’t a huge breakdown. [The Lightning] kind of stuck their stick in there on a net-front play that we had decent coverage,” Cassidy said. “Otherwise, I thought they played well, did their jobs. Again, we have – one line gets all our goals, so the rest of the group, if they’re not fine offensively, have to prevent goals then, obviously. And that’s part of it. You’ve got to bring something to the table. The guys we inserted, like I said, until the last shift, you can critique it however you want, as will we. But, [the Lightning] won a board battle and threw a puck at the net and got a fortunate bounce, and that’s that. I don’t put that all on the lineup changes.”

Cassidy may not pin the loss on the lineup changes, but a look back at his postgame quotes from Game 3 don’t necessarily jibe with the decision.

After that Game 3 loss, Cassidy said this: “I think we look slower than them. They are a fast team, so we expect them to play fast.”

After that Game 3 loss, Cassidy also said this: “If you’re not [scoring], you’ve gotta defend better, and that’s what my issue was. You need to bring something else to the table, and then eventually scoring will come if you’re a guy that’s scored in this league. I really believe that. And I think that’s where fundamentally we’re missing out on some of the players we rely on.”

Cassidy inserted Donato to hopefully get some scoring, but he inserted Gionta for reasons that perhaps can’t be fully explained.

And so, when it was Gionta — who is a minus-30 player with a 44.7 Corsi For percentage over the past four seasons — getting moved in front of the net as the game-winning goal was scored, and when that costly moment came one game after Cassidy stressed a need for the Bruins to defend their net better? It’s certainly a coaching call that’s going to draw some scrutiny.

For the time being, at least, Cassidy stands behind it.

You can email Michael Hurley or find him on Twitter @michaelFhurley.