The Capitals’ Tom Wilson is a predator who preys on defenseless opponents like the Islanders’ Lubomir Visnovsky, whom he finished off with an unnecessarily violent check in Tuesday’s Game 4 at the Coliseum.

But the subjective term “unnecessarily violent” doesn’t appear in the NHL rule book and isn’t a criterion on which the Department of Player Safety can impose supplementary discipline.

So Wilson, who was cited for a 2-minute minor for charging that he probably didn’t even deserve according to the letter of the law, was able to skate … not only from the league’s justice system, but into Game 5 and beyond.

This is nothing new for Wilson, who seems to play without regard or respect for the opposition, and who rarely confronts a foe straight-up and head-on. He is a fourth-line freight train who has made a career of coming at opponents when they are most vulnerable.

If there was any remorse for the hurt he put on the much-concussed Visnovsky, Wilson must have kept it to himself.

Every day, it seems, more players and former players are speaking about the effect of concussions. Mike Peluso was the latest, with a submission to Toronto’s The Globe and Mail about the debilitating impact a career of crashing and fighting has had on his life.

Daniel Carcillo’s video submission to The Players Tribune regarding the death of his friend Steve Montador and the “dark place” he himself experienced following a concussion was sobering, the identity of the messenger not detracting from his courageous message and challenge to the NHLPA to do right for players when their careers end.

Litigation continues against the league, with numbers of former players alleging the NHL was deficient in protecting them against the effects of head trauma throughout their respective careers.

And yet you have players like Washington’s Wilson and plays like the one in which he blasted Visnovsky into Never Never Land a tick or two after the defenseman had played the puck behind his own net. You have a total disregard for safety from one player to another.

Then, to add insult to injury, you had Brooks Laich following with unsavory comments on the radio, chirping about how Wilson’s charge was “a good penalty [because] … Visnovsky got knocked out of the game.”

Honestly.

Visnovsky’s career probably is over. Ryane Clowe’s career probably is over in the wake of multiple concussions. Kris Letang’s career in Pittsburgh may be over. Indeed, Slap Shots has been told Pittsburgh management would not allow the multiply-concussed defenseman to try to play against the Rangers even though he asked.

Concussions are a league-wide issue and a matter before the courts. But, as always, they are a player issue as well, as highlighted by players like the Caps’ Wilson.

The chants of “Katy Perry” from a segment of the crowd in Winnipeg meant to taunt Anaheim’s Corey Perry seemed juvenile rather than sexist, politically incorrect rather than discriminatory, and since when is an arena or stadium a gathering place for sophisticates?

Gary Bettman’s response on Friday to a question about it might have been expressed somewhat more artfully, but this isn’t an issue regarding which that either the commissioner or the league should be piled on. The NHL has been socially progressive on gender issuesand has been respectful of the role of women in the media and within the industry.

Sexism is a serious issue. I never would abide my granddaughter Reese being a victim of it. But I don’t think typically childish chants in the stands at Winnipeg last week rise to a level of concern. Seriously, not everything is meant to be taken literally or personally.

Can’t find many folks who believe Mike Johnston will get a second go-round behind the Pittsburgh bench.

Evgeni Malkin is in at a $9.5 million annual cap charge through 2021-22, so good luck to the Penguins trying to start their rebuild/retool by moving No. 71 for a package that might include the elite winger Sidney Crosby desperately needs by his side.

How many times in the five-game series against the Rangers — and how many times throughout the year — was Crosby wide open in great scoring position but failed to get the puck?

Seriously, it’s not like Wayne Gretzky ever had, say, Bill Berg on his line.

Oh wait. Yes, he did. Never mind.

Though you would have to say that No. 87 bears some responsibility of his own for having scored in two of the Penguins’ last 23 playoff matches.

So within days of hitting the Connor McDavid lottery, Edmonton’s hierarchy moved boldly to reverse the organization’s laughingstock image with the hiring of Peter Chiarelli to run the show.

It had been previously suggested to us that the Oilers would seriously consider dealing Taylor Hall this summer, but now all preconceived notions are on hold.

The challenge for Chiarelli is to avoid bringing used-up Bruins to Edmonton — Milan Lucic, anyone? — and to provide enough credibility so the organization doesn’t have to routinely overpay free agents in the form of bribes to come to his Alberta burgh.

Ken Hitchcock probably is coaching for his job in this first-round St. Louis series against the Wild, while Joel Quenneville, who has a lock on his in Chicago, sure came up with a curious choice for his Game 6 goaltender by going with Scott Darling rather than Corey Crawford yet again, didn’t he?

How about all those cars honking to the tune of “Let’s go Rangers” on Eighth Avenue following Friday’s first-round clincher?

Sorry, that was only traffic.

Too bad the Blues held that retirement press conference for Martin Brodeur, or he probably would be in nets for Game 6.