Just as he did last fall, when erroneous stories circulated that he was missing in stormy seas off the coast of Australia, Jack Nicklaus today turned up tanned, healthy and eager to asserted that reports of his death are greatly exaggerated.

This time, on the eve of the 43rd Masters Tournament, he was referring specifically to his golf game. Rumors of its demise, he said repeatedly, are vastly premature-eventhough he has played so poorly this year that he is not the pretournament favorite here for the first time in a dozen years.

I've been gradually working myself up to the Masters, probably more so than in a long time, simply because I'm tired of reading and hearing about how bad I'm playing, and answering questions about why," Nicklaus said after today's final practice rounds at Augusta National Golf Club.

"If I didn't mind reading those things, if I accepted them as a fact of life and it didn't bother me, because it would mean I didn't have the motivation anymore. But the tournament is not mine right now, and I've got to go out there and go for it. Maybe that's a better feeling for me to have."

The road to Augusta has not been a confidence-building one this year for the man who has won more Masters (five), more major titles (17) and more official career money ($3,360,702) than any other golfer.

His earnings of $11,309 place him 79th on the 1979 PGA Tour lst.

In his last previous appearance, the Tournament Players Championship at Sawgrass last month, he shot 82-78 the last two rounds. Incredibly, in his last 14 tournament rounds, Nicklaus has been under par just once.

Yes, the Golden Bear has been in hibernation. No denying that. But, he pointed out calmly today, he has had "dry spells" before in his peerless 18-year pro career. Those people anxious to bury any sporting Caesar have written him off in the past. He has proved them wrong, and he expects to do so again.

Like the flowers that make Augusta in the springtime such a joyous revival, the sleeping Bear is awakening.

"I feel like I'm starting to play very well right now. The three days I played here last week, I accomplished a considerable amount as far as what I wastrying to do with my swing. Working out at home (North Palm Beach, Fla.) over the weekend, and the last couple of days back here, I feel that i've been hitting the ball very well," he said.

"Obviously, since I haven't scored well up to this point this year, I don't know what's going to come out of my bag as far as scores go. But sooner or later, I'm going to start playing well this year, and i'd just as soon make it sooner."

Nicklaus, relaxed and expansive during a rambling 45-minute press conference, made it clear that his much publicized slump has caused him to particulahat his much publicized slump has caused him no particular high anxiety.

But he is tired of hearing about it, of being on the defensive, so today he took the initiative and said emphatically that he is not finished at age 39.

"I notice that every time I happen to play badly forabout a month you all have my obituaries written," said Nicklaus with agrin. Despite headlines to the contraty in sensational Australian tabloids, he was en route by air from the Philippines to Australia when stories of his probable drowning were falshed around the world last November.

"I assure you, I am not ready to drop dead yet," he said today.

"Frankly, I just haven't played well. I have no reason or excuse or anythingelse for it. But i've gone through many other spells throughout my golfing career where I haven't played well, and it's of no great concern tome.

". . . If I was playing the way I was six weeks ago, by all means I would try to find some way to get on and off the golf course without anybody seeing me.I hit the ball just about as poorly as I ever have atinverrary. I was awful in Florida. But i'm playing much better now, and maybe it's good that i'm not going to be favored for a change.

"Obviously, every time I pick up an article about golf and it starts, 'with Nicklaus no longer there . . . ', it irritates me. I don't like to read that. But the only way I can change it is to go out and play better."

It is a measure of his annouance, of the hurt to his professional pride, that Nicklaus anticipated the questions today and headed them off. Buthe admits that if he were an objective outsider looking in, he would not make himself the master favorite either.

He would likely go along with the odds posted by Ladbrokes, the giant British bookmakers, who made 1977 champion Tom Watson the top choice at 5-1, Nicklaus second at 8-1, defending champion Gary Player third at 10-1 and four-time runner-up Tom Weiskopf fourth at 14-1.

"The way I've played, I don't deserve to be favored. Absolutely not," Nicklaus said. "But does that mean that I don't pick myself inside?

"Obviously, considering the record, Tom (Watson) has played a lot better then I have, and so have a lot of other guys. But in my own mind, I don't look at things objectively when I'm trying toplay golf.

". . . The course is in excellent shape, I'm very optimistic about the way I'm playing it, and I'm quite anxious for the tournamentto begin."

Player, the 43-year-old South African who came from seven strokes off the pace on the final day to win his third masters green jacket last year, said he thought long-hitting Andy Bean is a good bet to win his first grand slam tournament here.

Ladbrokes listed Bean as a 16-1 shot, along with TPC champ Lanny Wadkins, Ben Crenshaw and Lee Trevino. Spaniard Severiano Ballesteros also was listed among the favorites, at 20-1.

But Nicklaus, typically, did not want to get involved in assessing the chances of other players. Asked to pick five men other than himself likely ot win, he said: "I could care less. It doesn't bother me at all. The only thing I care about is my own game."

He is getting his "game face" on and thinks he has made the technical adjustments necessary to reestablish his long-held superiority.

Nicklaus has strengthened his grip, as he did last summer just before wining the British Open and ending a three-year drought in the major championships.

"My wife, my kids, a lot of people told me that my lower legs looked very funny when I was swinging this winter. I think a lot of it had to do with a weak grip that didn't allow me any strength through the hitting area.

"I tried to compensate for that weakness and picked up a few other little flaws in the swing," Nicklaus said, launching into a lengthy discussion of the chain reaction that can turn a minor aberration into a major irritant in such a delicate mechanism as the golf swing.

"I adjusted my grip a few weeks agom and all of a sudden my lower legs started to work, and I've been hitting the ball much better ever since."