"I think he specifically wanted some depth players for that reason and to build our whole organization to have better depth. We saw it in one area of our team last year in the playoffs - on defense. We're trying to guard against that and make sure that we have quality people ready to go if there's a next-man-up situation.
"So far, so good. We've had good efforts from guys. I think they recognize the competition is there and that should make our team better."
During Wednesday's practice at Warrior Ice Arena, the Bruins had 19 forwards filling out six lines, meaning up to seven players could find themselves on the outside looking in when the season kicks off a week from Thursday.
Among those challenging for spots on the bottom two lines are youngsters Noel Acciari, Austin Czarnik, Jakob Forsbacka Karlsson, Danton Heinen, Sean Kuraly, and Frank Vatrano, as well as more experienced players like Kenny Agostino, Matt Beleskey, Teddy Purcell (in camp on a PTO), and Tim Schaller.
For those on the bubble, the final two preseason games (at Philadelphia on Thursday and at Chicago on Saturday) become magnified.
"If you play on your heals, you're not going to give yourself the best chance, so keep pushing and the second you step back and start thinking about that stuff other thoughts get in your head," said Kuraly. "It's about playing hockey and moving forward and realizing that that's going to give you the best chance."
Cassidy believes those with the most versatility - particularly those who can contribute on special teams - will emerge from the pack, while also hinting at the possibility of the Bruins having different lineups based on the opponent.
"One hundred percent…guys have different attributes," said Cassidy. "They've got to be able to play 5-on-5. But throw Tim Schaller's name out there…very good penalty killer - getting better in that scenario of the game - where he could separate himself from [Kenny] Agostino, who is in the mix and is more of a skill guy and may contribute on the power play."
"What's our bigger need from night to night? It could come down to that where we use a different player every night."