While his Minnesota North Stars skated on the Nassau Coliseum ice this morning, Coach Glen Sonmer jogged around the concourse. Tonight, when the Stanley Cup final series opened against the New York Islanders, the entire Minnesota team might as well have taken a hike.

The Islanders, with Anders Kallur and Bryan Trottier scoring short-handed goals during one first-period penalty, breezed to a 6-3 triumph that came so easily one exuberant fan shouted, "Islanders in three."

It still takes four victories, however, to win the Stanley Cup and the North Stars will be back here for a second try Thursday night. They figure to do better, simply because they could hardly be worse.

"They just thoroughly outplayed us," Sonmor said. "The most condemning thing for us tonight was that we stood too much with the puck. We need to get skating and not standing."

On a night when high-scoring Mike Bossy did not manage a point, Kallur and Wayne Merrick, two of the lesser lights in the Islanders' star-packed stable, contributed two goals apiece. Trottier's goal, at 14:38 of the first period, extended his record Stanley Cup point-scoring streak to 21 games, and it had the effect of a Gerry Cooney haymaker.

Kallur's deflection of a Dave Langevin slap shot at 2:54 sent the Islanders ahead, which was bad enough, because they had won all eight previous playoff games in which they scored first. But the North Stars' hopes were raised at 11:12 when Islander Bob Bourne was caught spearing Brad Maxwell, a violation that calls for an automatic five-minute penalty, to be served to the finish no matter how many power-play goals the opposition scores.

In those five minutes, Minnesota managed one shot; meanwhile, the Islanders scored twice to set a Stanley Cup record of nine short-handed goals, two more than their mark in winning the Cup a year ago.

Islander rookie Billy Carroll took the puck away from Craig Hartsburg in the Minnesota zone and Hartsburg was slow to react, permitting Carroll to forge a two-on-one break with Trottier against Maxwell. When Maxwell opted to go for Carroll, the youngster sent a perfect pass to the unguarded Trottier, who made it 2-0.

The sellout crowd of 15,008 was still celebrating that effort when Trottier outfought Gordie Roberts for the puck behind the Minnesota net and passed it out to Kallur, who scored from close range just 47 seconds after Trottier to make it 3-0.

"We just seemed very tentative and hesitant on the power play," Sonmor said. "Of course, a lot of that was due to (Butch) Goring and Kallur and Trottier. They attack and throw you off. With a five-minute power play, we had a chance to get two goals. Instead, they got two. A four-goal swing, that's enough.

"That just sunk us," said Bobby Smith, the big center who is a key to the success of the Minnesota power play. "We had a chance to go ahead and instead we're down, 3-0, and they're flying. That's very disheartening for a team. Their penalty killers keep you aware of both ends of the rink. A lot of penalty killing units don't attack that way."

"I thought we had it won after that," said Goring, probably the best penalty killer in the NHL. "It was a big lift for us. We knew if we worked hard we'd win it. First we got into that mess and we thought we'd have to work hard to kill the penalty. Then we score twice. It had to take a lot out of them, too. They had to be thinking, 'We blew it.' They had to figure they lost the game there."

Before Bourne left the box, Kallur sailed in on a breakaway with a chance for a third short-handed score. Gilles Meloche managed to smother it between his pads, although he was looking behind him in trepidation before realizing he had stopped it.

Besides the 3-0 lead on the scoreboard, the Islanders dominated every phase of the game. They outhit Minnesota, even Bossy knocking Steve Christoff back 10 feet with a solid check. They controlled the faceoffs by 19-7. And goalie Bill Smith, with Christoff shooting toward an empty net, reached out with his stick to make a seemingly impossible save.

There were questions about possible jitters by the young North Stars in their first Cup final and Hartsburg said, "It could be, but that's no excuse. We just didn't play well in the first period and those two short-handed goals killed us."

Goring, cut from lip to chin by Dino Ciccarelli's skate in the third period, still managed a smile afterward and said of the Islanders' potent penalty-killing unit, "I think this team has more talent than most killing penalties, not just the forwards but the defensemen, too."

He need not have restricted the comment to the penalty killers.