After a couple weeks of the Blackhawks’ effort meter flickering up and down, it crashed to near zero in their penultimate game Monday.

Mental and emotional engagement were visibly lacking in a 5-1 loss to the Sabres, who are heading to the playoffs for the first time in 15 years.

Nothing summed up the Hawks’ futility more than a line change after a penalty kill that they bungled to an almost comical degree, allowing Tage Thompson to bury the Sabres’ fourth goal.

Later, the Hawks’ backcheck after a turnover by Wyatt Kaiser in the offensive zone was arguably even lazier than the line change.

An announced crowd of 17,056 — which appeared several thousand short of that figure — missed no opportunities in the third period to boo the Hawks, to the point that in-arena host Jon Hansen joked about it during a commercial-break gimmick.

If it didn’t happen in the 81st game of a going-nowhere season, this kind of performance would justify a reckoning about the fitness of the Hawks’ roster and coaching staff. Considering it was, it instead can — and will — be forgotten soon.

Nevertheless, the atrocity that is this season-ending homestand — during which the Hawks already have been outscored 17-6 ahead of their finale Wednesday against the Sharks — is destroying optimism at a brisk pace entering the offseason.

“It’s a little unfortunate these last couple games have gone this way because, honestly, we’ve done tons of good things to build this in the right direction, and unfortunately, this sours your taste,” coach Jeff Blashill said.

“When you play great this time of year, it can fool you. When you play poorly this time of year, it can fool you.”

Against odds

The Hawks will finish in the bottom three of the NHL for a fourth consecutive season, becoming the first team since the 2001 Lightning to “achieve” that distinction.

Their 31st-place finish means they’ll enter the draft lottery on May 5 with a guarantee of a top-four pick. They’ll also have the second-best odds to receive a top-two pick.

Those odds still aren’t very high: 13.5% of getting the No. 1 pick and 14.1% of getting No. 2. It’s more likely they end up with the third or fourth.

Toothless Nazar

All things considered, Frank Nazar avoided the worst-case scenario when another puck struck his face Saturday in the Hawks’ loss to the Blues. But his two top front teeth did not.

The puck knocked them out, leaving him with a gap in his smile Monday and some swelling in his lips. He started the game wearing a cage, then switched to a bubble.

“I still got it pretty good, but it could be a lot worse, so I’m pretty thankful,” Nazar said, struggling to pronounce words correctly with the missing teeth.

“If I’m lazier, I’ve got a little bit of a lisp. But if I’m more firm, you can kind of understand me.”

Unsatisfied Greene

Ryan Greene reached the 10-goal mark in his rookie season with his goal Saturday, then tallied his 11th goal shorthanded Monday.

The quantity of chances he has missed still “doesn’t sit well” with him, though. He analyzed his overall performance this season as “responsible” but unspectacular.

That aligns with Blashill’s recent comments about Greene being a player he trusts to not let things get “bat-[expletive] crazy.”

“You kind of know what he’s going to do,” Blashill said.