When Denis Polvin, at age 22, was awarded the Norris Trophy as the NHL's best defenseman last season, it was assumed he was on his way to hockey's promised land, a lucrative and happy career.

A new five-year contract, confirmed in August, took care of the lucre. But happiness proved elusive, and it is a somewhat disillusioned Potvin who leads the New York Islanders into Capital Centre today for a 1:30 matinee with the Washington Capitals.

A lot of people, including this backer of Philadelphia's Jim Watson, felt that Potvin won the Norris because of New York generated publicity rather than any big performance margin over his peers.

The publication of the NHL's closely guarded plus-minus figures tended to support the losing candidacies of Watson, Guy Lapointe and Larry Robinson. Potvin's plus 12 rating placed him 13th among the Islanders. It was minuscule compared to Watson's plus 65, Lapointe's 64 and Robinson's 50.

Then Potvin went off to assist Team Canada in its crusade against Czechoslovakia and the Soviet Union in the Canada Cup. He played very well, in fact he thought he was Canada's best player. Those who selected the award winners were most favorably impressed with Bobby Orr.

Potvin kept a diary that was published in The Canadian, a national magazine, in which he expressed his frustration over Orr's repeated honors, his dissatisfaction with the coaching staff and his anger with the fans in Ottawa, where he played junior hockey.

"I don't think he (Orr) was deserving of the award twice and certainly not three times," Potvin wrote. "Once, yes; he did deserve it once. It's not Bobby who does the voting, but the ones who do seem to be more influenced by a big name and past reputation rather than what happens in a particular hockey game.

"I think it's political and I think it's unjust. The question I'd like answered is this: Is Bobby Orr only going to have to play to be known as the best defenseman - or is he going to have to prove it.

Angered because coach Scotty Bowman did not start him against Finland in Ottawa. Potvin wrote, "Even when I was on the ice, there was no recognition from the fans, nothing to say they appreciated my six years in that same rink as a junior . . . I've never felt as though I've ever received any gratitude from the people of Ottawa, specifically, the fans . . . One thing I know for sure: if ever the opportunity arose for me to go back to Ottawa to play again, I would never go back."

Reporting to the Islander's camp, Potvin expected to assuage the curiosity of his teammates about his Canada Cup experiences. Apparently, those teammates displayed no interest whatever. He was recently quoted as saying that nobody asked him about Team Canada.

Potvin and his wife, Debbie are not the typical hockey couple. They read a great deal, and not the ordinary paperback trash. They visit museums and art galleries, study the history of art galleries, study the history of art, furnish their condomium with expensive paintings and travel extensively in the offseason.

Last year the outspoken Potvin was quoted on the subject of his fellow players: "I guess you'd have to say many of them just kill time between games. Many are growing, but many are not. Many are wasting their youth. The city has more to offer than any other in this part of the world. It seems a shame that many don't take advantage of it."

With this background, it is not difficult to understand why the high-salaried Potvin and his teammates have little in common. yet, Potvin apparently wants to associate with them off the ice, while they prefer each other's more pedestrian companionship.

A New York paper recently spotlighted the loneliness of the Islanders' wordly young hockey player and inadvertently supplied the ultimate put-down. With the story, it ran a picture captioned "Denis Potvin." The man in the photograph was Mark Spitz.

For all his problems, Potvin is enjoying another fine season. Before last night's game with the Capitals as Nassau Coliseum, he had collected 12 goals and 29 assists to lead the Islanders in scoring. He remains accessible to the media, perhaps the best interview in the league. He can talk, and talk incisively, about any phase of a hockey game.

From a sportswriter, this is hardly a logical admonition, but perhaps ahe would be better advised, once in a while, to shut up.