About halfway through the game, Colby Cave was bumped up to the Bruins' first line to center Marchand and Pastrnak. Cassidy was not pleased with the compete level of Jakob Forsbacka Karlsson and felt a change was needed.
"I didn't like his compete tonight. Listen, we've talked about it. He needs to bring it every night," said Cassidy. "If he's gonna play with those guys, it was [Sidney] Crosby, it's [John] Tavares - it's a big ask. I've said it too, we saw something we liked, we moved him up. Tonight we didn't see as much of it.
"We moved Colby up. JFK [is] a little more comfortable down as third-line center. Going forward, until we get Bergy back, it's a work in progress. I thought Cave responded well. It's his opportunity, he wants to take advantage of it and he's doing whatever he can."
Cave, who has played three games since being recalled from Providence, jumped at the chance to play with what he called two "MVP-caliber" players.
"It's pretty cool lining up with those guys," said Cave. "They're gonna find you wherever you are. Just got to work hard to find the right spots…these guys are world-class players, they're both MVP-caliber guys.
"It's pretty easy to follow those guys on and off the ice. They're leaders, so you just want to do the same thing they're doing - work hard on and off the ice."