Déjà vu all over again?

“I don’t want to be disrespectful to the D-corps,” Bruce Cassidy said about the talent pool he needs to wean down after Thursday’s 2-1 OT win over Philadelphia, “but I think it is deeper up front.”

Before the first playoff faceoff last April, it was Torey Krug, then Brandon Carlo, then Adam McQuaid. And then Colin Miller during the Ottawa series.

A M.A.S.H of black and blue on the Black and Gold blue line.

All those injuries pressed rookie Charlie McAvoy into full-time duty just three weeks removed from NCAA play at Boston University. Heck, even Tommy Cross was called up for the playoffs when Rob O’Gara went down for the P-Bruins.

All told, the Bruins went to their No. 11 defenseman before exiting the 2017 season. Against Ottawa, the B’s top four were Zdeno Chara, Kevan Miller, McAvoy and John-Michael Liles.

Colin Miller was taken by Las Vegas in the Expansion Draft. Liles and Joe Morrow were not re-signed.

GM Don Sweeney again rolled the dice – to this point – that his D-corps was deep enough out of the blocks, adding only one free agent in Paul Postma from Winnipeg for a lowly $725,000 one-year deal.

Tuesday night, Carlo and Krug returned to TD Garden for the first time since last season. Only Carlo finished with Krug taking a puck to the jaw, and now out for at least three weeks with a non-displaced fracture.

This begs the question, who replaces Krug on the ever-evolving fractured Bruins blue line with opening night a fortnight hence.

In Thursday night’s preseason encounter with the Flyers, Cassidy dressed a D-corps of Chara, Carlo, Cross, Matt Grzelcyk, Jeremy Lauzon and Postma.

Raise your hand if you see any combo of that group beyond Chara and Carlo as blue-line staples on October 5. Which begs the early question about what the starting D-seven looks like as the Bruins work through roster maneuvers the next two weeks to the season opener.

Right now a top-5 looks like Chara, Carlo, Miller, McAvoy and Adam McQuaid. OK, not too shabby. But what comes for 6-8? Throw a net over Postma, O’Gara, Grzelyck, Cross, 2015 first-round pick Jakub Zboril, Jeremy Lauzon, Chris Breen, Connor Clifton, Taylor Doherty, and Emil Johansson.

“We’ve got a lot of first year guys coming into the back end,” Cassidy said postgame. “[Jeremy] Lauzon, [Jakub] Zboril, Emil [Johansson], who hasn’t played yet, Griz [Matt Grzelcyk], and [Rob] O’Gara, second year, but O’Gara missed the end of last year so not quite as much depth. [Paul] Postma is a good add. He’s played in the league and so has Tommy Cross. Losing Torey [Krug], depth or not, he’s our best puck-moving defenseman. He’s a very good offensive defenseman and a good 200-foot player.”

Several of the aforementioned defensemen will be pared.

Not exactly, however, a roster of household names is left in any order. Not to mention creating another mega task for Tuukka Rask who made his first start Thursday and played all 60-plus minutes with Postma netting the B’s first goal. He had 15 points in 65 Jets’ games last season.

OK, it’s just the preseason. Nonetheless, the D is a recurring concern in the Hub of Hockey where it looks like a few new faces on offense and ditto on D are coming with the “O” having that deeper talent pool?

“I still think there are good players, and we’ll have six of them opening night that are just going to have to get the job done,” Cassidy said with fingers likely crossed.

“Nobody’s asking anyone to do too much,” Rask said about the evolving defense that is key to his successes, “just make the play when it’s there, and protect the house when needed.”

A year ago to the day, Brandon Carlo was given the task of becoming a top-5 defenseman before his first NHL game. “I feel like everyone in this group, including the young guys and prospects, can definitely come out there and handle themselves,” he added.

A few newcomers will have to handle themselves and protect that house – again – in 2017-18.