The Bruins were playing their third game in four nights, but were not interested in using late-season fatigue as an excuse for their efforts.
"We've said that all along, that it's going to be that type of hockey for the rest of the year," said Patrice Bergeron. "It's part of realizing you can't take the night off no matter what night it is, or who you're playing, or what happened the night before. You have to be at your best and we didn't do that tonight."
Cassidy was not pleased with the Bruins' first period - during which Boston was outshot, 17-8, while managing to keep the game scoreless - but believed his team could have changed the course of the night with a fortunate bounce. Had Bergeron's shot from the slot not clanked off the post in the opening frame, the Black & Gold could have been playing from ahead.
And it was only a few moments after Brian Gionta's tally was wiped off the board early in the second for corralling the puck with a high stick, that Brayden Point gave the Lightning the only cushion they needed.
"That could deflate them because they were playing the way they wanted to play, finishing checks," Cassidy said of Bergeron's near miss. "They were winning most of the loose pucks. Maybe a play or two we come out of that…we weren't able to play through those. We had to play through that and make sure when it was 1-0 or 2-0 you get the next goal and not get behind three. They're too good a team."
Instead, Tampa went on to score three second-period goals, before delivering the final dagger just 2:34 into the third on J.T. Miller's 23rd of the season.
"I thought a lot of our young guys got an education tonight on what it takes and I'm not putting this on them," said Cassidy. "I'm just telling you the experience they gained tonight understanding the urgency level was very good for them in the long run…good for them to learn that because that's what they're gonna see next week [in the playoffs] and they need to be able to play in those types of games if they expect to be in the lineup. It's not all bad for them to go through that."