That balancing act is one that Cassidy will have to wrestle with through the final regular season game against the Panthers on Sunday night at TD Garden. The Bruins are still trying to get their group healthy, with the likes of Rick Nash, Riley Nash, and Sean Kuraly working their way back from injury.
But Boston is also in prime position to capture the top seed in the Eastern Conference. After Tuesday night's loss, the Bruins are tied with Tampa Bay at 110 points, but have one game in hand.
"I feel good, I want to play a full season…don't want to talk about [rest]," said David Pastrnak, one of two Bruins along with Tim Schaller to have skated in every game this season. "We have three game left, we want to win all of them and see how we end. It would be nice [to get the top speed]. It's what we work the whole season for, get ourselves a good spot.
"We don't think about it, we think about the next game and get back on track tomorrow night."
Depending on what the implications are on the standings, Cassidy will have to decide whether or not to dole out rest or play everyone through the year's closing weekend.
"We're gonna try to beat Florida tomorrow, to be honest with you," said Cassidy. "We said this before, we're going to decide on the rest accordingly. We'll talk to players individually. Some of the guys that have played a lot of hockey are out, one permanently [in Brandon Carlo]. [Riley] Nash and Kuraly played a lot, so they're getting their rest now, for lack of a better term. Zee and Charlie got some time off, Bergy, [David] Backes.
"You've got some guys like Schaller, Marchand, [David Pastrnak] that have played a lot of hockey - Marchy had a bit of a break - Krug, [Matt Grzelcyk], [Kevan] Miller. We'll monitor that going forward. We've tried to limit practice time."
Backes believes that any rest the team might require can come from within with a bit of teamwork.
"Some of it might be physical, but some of it might be mental, staying with it, staying on that edge," said Backes, who has suited up for 54 games this season.
"The rest of us that have maybe not played all the games, it's up to us to grab that rein and say, 'Hey maybe I can do a little bit more if the work tonight.' Not necessarily give other guys breaks, but let them use their brain and maybe hold back."