When Jack Nicklaus emits his first major growl of the season, the golf world has no choice but to take note. Like the Dallas Cowboys, the New York Yankees and, perhaps, the Boston Celtics, the Golden Bear is America's team in golf.

When Nicklaus shot 66 in the final round of the Honda-Inverrary Classic last Sunday to finish second to Johnny Miller, it was the first noise from Nicklaus since he saw a fifth U.S. Open title snatched from his paws last June at Pebble Beach by Tom Watson's instant-legend chip-in on the 71st hole.

Nicklaus is a student of games and has a sense of how the personal histories of great athletes are often changed or redirected by one dramatic event. He's anxious that Watson's moment of ascendancy not coincide with his own demise.

Nicklaus now admits Watson's shot had been "enough of a blow to end my desire for the year," but that he had to be "man enough to come back from it, although sometimes it takes some time."

Now, Nicklaus is making a determined effort to find out if he is still, at age 43, a great golfer, or if he has, indeed, reached the stage where it is time to start rounding off the edges of his sport's greatest career.

The consensus among Nicklaus watchers is that he's working harder this spring than at any time since he became a conglomerate more than 15 years ago. In fact, he may be pouring more hours into the sport than at any time since he was a teen-ager. That alone, however, no longer assures victory.

After two months of intense practice, Nicklaus said of his game: "I'm not particularly happy with it. I've played reasonably solid golf, but I haven't done that much. I haven't hit the ball nearly as well as I usually have. Obviously, I don't have many years left (at the top).

"There's more quality on the (PGA) Tour now than ever. It's just harder to get to the top of the heap and stay there. The play is so much better than it was five or 10 years ago--pick any interval you want--that it just amazes me, week to week. For instance, I played a pretty good tournament at Doral and I wasn't close.

"There's always a next wave of good, young players, and I hope I'm there to be the one they challenge," he said. Then, the instinctively honest Nicklaus brought himself up short. "Of course, I'm the guy doing the challenging now. There are a few fellows playing better than I am now."

It has taken years for this concession to escape his lips. For several years, some of the younger players have felt a slight annoyance toward Nicklaus for believing for too long that he was still king of the hill.

Of all the difficulties associated with Nicklaus' advancing athletic age, one has become his biggest, insoluble bugbear: to play or not to play.

Nicklaus' greatest strength has always been his enormous capacity for relaxed concentration on the course. In recent years, he's found it impossible to maintain his appetite for the game and his concentration if he plays much more than 12 to 15 times a year; that's barely half the number of tournaments some pros play. "I find it hard to play week after week," he said. "It takes its toll later in the season. I want to enjoy playing because that's when I've played best."

On the other hand, the first skill that often disappears with age or success is the indefinable knack of turning good golf shots into great scores. Call it "scoring touch" or "course management" or whatever, the constant moan of aging Palmers and Nicklauses is: "I hit it like 68, but I shot 72."

For 1983, Nicklaus' plan has been to practice hard all winter on his putting and short game, then play more spring tournaments than he has in years, hoping to iron out his swing and his mental toughness.

Fittingly, his approaching middle age, and inevitable withdrawal from center stage, may be made easier by the exploits of his fourth child, 14-year-old Gary.

Gary, an eighth-grader, is already a scratch player who is No. 1 man on a top high school golf team. Nicklaus, after seeing his boy shoot 66s and win tournaments by nine strokes, said, "He has a better (more imaginative) short game than I do right now. He and I both took lessons together from Phil Rogers and he just loves to practice those little touch shots . . .

"What's scary is the parallels between us," Nicklaus said, beaming. "He enjoys having me watch him and work with him, just like I did with my dad. It doesn't bother him. Instead of being intimidated, he likes to show what he can do.

"He's going to be good. Of course, you realize that's a father's completely unbiased opinion."