The Bruins weren’t at their best Saturday night, but that has become the standard of late, the consequence of living the nightly NHL life without Patrice Bergeron, their top forward, Zdeno Chara, their captain and No. 1 blueliner, and Charlie McAvoy, their wunderkind defenseman.

Remove the 3-4-5 hitters out of any lineup, and it becomes, shall we say, a challenge.

So, it’s really no surprise that they were rubbed out, 4-2, by the Red Wings, a team in rebuild, compared to the Bruins, a team mostly in rehab, emergency rooms, and various bandages, splints, walking boots, and full body casts.

“Watching the video tomorrow morning, I will,’’ said coach Bruce Cassidy, asked if he ponders, during games, the fact that his A-list players are hors de combat. “Tonight . . . no . . . I just think it’s a bad road to go down . . . the what ifs, the woe-is-me’s. We are winning games with this lineup. Tonight we didn’t, but we’ll bounce back Tuesday.’’

The Bruins were 6-2-2 in their 10 games leading up to to the Red Wings visit, still tucked in among the top 10 teams in the Original 31 and tracking well toward a third straight playoff spot. Respectable.

All the more so when again considering the general state of the Black-and-Gold’s un-well being. And the fact that it has become such a challenge to score (now 15 goals in their last eight games, only 10 of those at even strength).

The NHL, which is certain to add a 32nd team this week, with Seattle awaiting a rubber stamp on its $650 million entry fee, maintains its status as the best hockey league in the world. It is also a developmental league, with all teams forced to patch in kids who aren’t quite prime-time players. That’s the reality of trying to come up with the 620 best players in the world to stock those 20-man game rosters. The talent begins to thin out considerably after the upper crust of, say, 350-400 players.

Long ago, it was the task of the minor leagues to sort out the prospects, projects, and pretenders. That’s now the charge of NHL bench bosses like Cassidy, who has done a brilliant job of coaching up kids since taking over the bench here less than two years ago.

Are some of his asks too big lately? Uh, yeah. Witness the recent attempt to force feed Jakob Forsbacka Karlsson into the No. 1 pivot job normally occupied by Bergeron.

JFK had some moments, but he struggled, leading Cassidy to try another kid, Colby Cave, in that top spot of late. Cave has a bit more moxie to his game, but he also isn’t ready for that leading role. By game’s end Saturday, desperate for a tying goal, Cassidy moved David Krejci to that penthouse spot, flanked by David Pastrnak and Brad Marchand.

But the asks will continue, in large part because Cassidy has no other options.

Unless GM Don Sweeney can find some answers in the trade market, Cassidy has little choice but to replace, patch, and develop. Round ’em up, coach ’em up.

All the while praying he sees a plume of white smoke emanate from the MGH chimney.

Are his asks too big?

“They never will be, because it’s the NHL,’’ he said. “If they want to play here, they’re going to get asked a lot. It doesn’t mean we’re going to, you know, get it. What we do demand is to get better competitiveness, practice hard every day to get better. Not to try to get away from the question, but tonight they were up against it a little bit. They’re going to have their ups and down, so I guess that’s the best way to put it.’’

Cassidy’s results since taking over here: 82-35-17 through 134 games. In hockey math, that works out to a robust .675 winning percentage.

No doubt, that number has been helped immensely because he inherited a roster with a No. 1 stopper in Tuukka Rask, elite wingers in Marchand and Pastrnak, and the aforementioned key missing parts, particularly Messrs Chara and Bergeron.

“We’ve got good players in that room,’’ said Cassidy, refusing to lean on the injury crutch, which right now could supplant the Spoked-B as the team logo.

“We’re hanging in there, playing good, hard hockey. Of course we’re going to miss our best players. We miss Bergy. We miss Z. We miss ’em all.’’

The void would feel far bigger if not for how the coaching and the kids have helped keep a handicapped roster near whole. Only one-third of the way into the season, the Bruins already have used 12 defensemen and 15 forwards, a total of 27 bodies to fill those 18 skating positions.

The pain has been felt most of all in back, on defense, where five key players already have missed 63 games: McAvoy (19), Kevan Miller (15), Torey Krug (11), Brandon Carlo (10), and Chara (8).

So, until bodies get better, or Sweeney gets better bodies, there will be more nights like this on Causeway Street.

The Bruins can scrap and scrape along, but rare will be the night they truly can separate from their competition, put away teams with conviction. They haven’t won a game by more than a goal since Nov. 11 (4-1 over Vegas).

It’s hold on, develop, wait for bones to mend, soft tissue to heal. The Black and Gold remain in a state of Gray’s Anatomy.

“Hopefully,’’ said Cassidy, pondering the need for kids to to step into roles, “they realize it’s a 60-minute game and an 82-game league. You’ve got to bring it every night.’’

Kevin Paul Dupont can be reached at kevin.dupont@globe.com. Follow him on Twitter @GlobeKPD.