Mike Sullivan has directed a blunt missive to his team in recent days. “We’ve got to be harder to play against,” the coach said Wednesday. That may leave some room for interpretation, but in practice Thursday, it translated into a physically demanding session.

Players hit the ice — literally — when teammates checked one another in a furious fashion along the boards while battling for pucks. It was as intense a practice the team has conducted all season, including training camp. But all of those shoves, cross checks and bellicosity Thursday were for naught as the Penguins suffered another loss Friday, this time falling to the imposing Winnipeg Jets, 4-1, at PPG Paints Arena.

The Penguins lost for the seventh time in their past nine games (2-4-3), while the Jets improved on their NHL-best record, boosting it to 17-3-0. Penguins goaltender Tristan Jarry, who was booed when announced as the starting goaltender for the second consecutive home contest, received even less support from teammates, who fumbled a puck in their own zone, allowing Jets forward Nino Niederreiter to score his eighth goal only 82 seconds into regulation. Racing back for a loose puck near his own left corner, Penguins defenseman Marcus Pettersson rimmed it along the end boards, presumably for defensive partner Erik Karlsson in the opposite corner.

Karlsson and Penguins forward Evgeni Malkin appeared to get their wires crossed on the sequence, and Malkin batted the puck into the lower-right circle. J.