Prust and Stepan claim each other as a friend, which is part of the charm of playoff hockey. Teams list injuries as vaguely as possible — “upper body” or “lower body,” meaning the aggressor has to be a generalist rather than a specialist. Otherwise, the boys would zero in on a wobbly elbow or aching calf.

For example, the Montreal coach, Michel Therrien, said early Sunday that his team knew exactly what was ailing Derick Brassard, the Rangers center who has been out with what was described as an upper-body injury.

The Canadiens might have tried a little exploratory surgery to see what was ailing him but Brassard converted on a fast break late in the second period to give the Rangers a lead.

In between veiled threats, there are a million nasty tricks, like a sweaty glove with a residue of ice, mashed into the puss of an opponent during a clinch in the corner. Just because.

This sustained hostility makes hockey different from any other sport. Baseball’s postseason shifts from game to game because of starting pitchers and the geography of the ballparks. The football playoffs feature one-off affairs, without bad feelings building from weekend to weekend. In addition, football uses platoons for offense and defense and kicking, so only the interior linemen have a chance to really get up close and personal with one another. The long dunkathon of basketball can be nasty as well as spectacular, but technical fouls and personal fouls and the three-dimensional aspect of the game (some players levitate above trouble) tend to cut down on repeated aggression.

Soccer comes the closest to hockey in the building of momentum. During the recent Champions League, Atlético Madrid muscled aside smooth Barcelona in the two-match quarterfinals, matching its hard-shell coach, Diego Simeone. On Saturday against the perennial champion Real Madrid, injuries and weariness started to cut into Atlético’s intensity and Real’s desperation — and talent — ultimately prevailed, 4-1. After that, Simeone lost his mind, racing around the field, looking for trouble, reminding me of the cloddish rampage by one hockey coach toward an opponent’s locker room this season. That was John Tortorella, the former coach of the Rangers, who had moved on to coach Vancouver.