Jimmy Connors, no longer the isolated man of pro tennis that he was several years ago, was sitting in the lobby of a Philadelphia hotel one afternoon last week - "Just shooting the breeze," as he says, wth some of his colleagues.

Ilie Nastase, the well known Romanian who remains Connors' best friend among the players on tour, handed him the latest issue of "International Tennis Weekly," a trade newsletter. Its lead story was about Connors winning the $400,000 Colgate Grand Prix Masters at Madison Square Garden, the first big tournament of the new calendar year.

"They don't say nothing nice about you," grinned Nastase, Connors' erstwhile doubles partner and Brother of Invention, bad taste division. Some called them "the vulgarity twins."

"They better," Connors retorted, smiling back like the cat who swallowed a flock of canaries. "I was nothing but a perfect gentleman."

James Scott Connors will never be mistaken for a perfect gentleman, either on the court - where occasional fits of snarling, cursing and rude gestures seem to provoke his best tennis - or off.

It is simply not his nature or upbringing. He is strongwilled, independent, proud and fiercely competitive. He is also part of a generation that has grown up accustomed to coarse language, selfishness and X-rated behavior. Most of the time it doesn't occur to him that his off-the-cuff blue remarks or body language still shock and insult some people. Like Frank Sinatra, one of his heroes, it is his inclination to go through life singing "My Way."

Connors would love to be as good a natural comedian as Nastase but for all his natural star quality and that unquenchable twinkle in his eyes, he can't quite pull it off. Instead of Nastase's off-court savior faire, he has uncanny knack of unintentionally good-natured prank seem sophomorie or boorish.

One evening in Philly, for instance, Connors and Eddie Dibbs got in the elevator together. Connors was going to the 10th. When he alighted, Connors quickly reached back inside and jabbed all the buttons from 5 through 10. "Take the local," he hee-hawked at Dibbs. Only ten did he seem to notice there were others aboard, and mumbled a hasty apology.

The next afternoon, he was sitting in the coffee shop with a group of other players. He made a loud off-color remark about his admittedly off-color lunch. At the counter 25 feet away, Jeff Borowiak - a senior at UCLA when Connors was a freshman in 1971 - frowned. "Jimmy, we can hear you all over the restuarant." he said.

"Then you must have bionic ears," Connors shot back momentarily irked. But then he look genuinely embarrassed.

If Connors will never be an angel or a model for Boy Scouts, he is at least making an effort to reform. He insists he doesn't care whether he is loved or hated - "people can root for me or against me as long as they're involved" - but deep down it is obvious that he wants to earn the respect as an individual that he already has as a player. He wants to be liked and accepted.

Among his peers - who have forgotten 1974-75 when, puppeteered by maverick manager Bill Riordan, he was the anti-establishment champ, suing the officers of the Association of Tennis Professionals - Connors is already accepted.

"Jimmy isn't out to kill the world or anything like that. People have long considered him the outsider, but I don't think that was necessarily his own doing," said Roscoe Tanner, whom Connors beat, 6-2, 6-4, 6-3, in the final of the U.S. Pro Indoor championships on Sunday.

"Guys started cold shouldering him when Riodan (whom Connors dumped in late 1975) was around because he was the front for some things that hurt the game. But I think Jimmy just decided there was more to life than tennis. He didn't want to be hated. Now he gets along with all the guys fairly well, and they like him."

"It is more difficult to change the prevailing public perception: that Connors is the most dynamic and exciting player in the game, a commanding personality, but not necessarily one that merits pride or respects. While he has some devoted fans, there are at least as many people who can't stand him.

Connors thinks that his reputation is partly a bad rap, or at least an outdated one.

"I was pretty young when I started doing well in tennis. I was a little immature, and maybe I got branded early with a bad image. Its tough to change that," he said.

"And the public only sees one side of me. I'm a differnt person on the tennis court, no doubt about it. The style I play, the things I do, the way I try for every ball and fly through the air and all that stuff - let's face it. I'm an animal. I give everthing I've got every time I go out there, and I'm proud of that."

Swagger, cockiness, the supreme self-assurance to slug uncompromsingly for the lines when a match is at its tensest is an important part of the Connors style. He always bores ahead, full throttle, in a manner that requires a certain pugnacity. There is no prouder or more ferocious competitor. "People say I have an arrogant gait," he once said, "but I must have come out of the womb that way, because I've always walked the same."

If his basic temperament is unchanged. Connors is certainly making a determined attempt to shed his "last-angry-man" image. He is obviously relaxed and enjoying himself these days. Sometimes he borders on being downright charming.

At Philadelphia he won over crowds with good-natured clowning and a minimum of obstreperous antics, and the media with long, cooperative press conferences. He was chatty, agreeable, pleasant. He said over and over that tennis is fun for him - now the matches and the various pre- and post-match abligations and preparation that make playing a tournament a 24-hour affair.

"I took six weeks off between Novermber and the Masters and that was the best thing I've ever done," said Connors, who turned 25 in September. "When I'm at a tournament, everything revolves around tennis. I sit around for nine or 10 hours before an evening match. Your rest, your meals, everything depends on the tennis. You can't go out shopping or doing things you enjoy, because that uses up energy.

"People think this is a glamorous life, and at times it is. But other times aren't so glamorous, and that's part of the business, too. You take the bad with the good.

"I space out my tournaments now, to be rested, relaxed and eager so I play my best tennis. I'm in the fortunate position that I can pick and choose my spots. I don't have any trouble finding someplace or somebody to play.

"It's important to me to enjoy it now, because when I do go out and play somebody who's 17, 18 or 19 years old, I remember how it was when I was that age, I was pretty well fired up, always eager to play somebody 25 or 26 and at the top.

"There are a bunch of guys that age coming up now, and I'm the guy they make their names off of. I'm not ready to give anybody a name at the moment, so I might as well be prepared to kill myself everytime I play, so for the next couple of years I can stay where I like to be at the top. Before I was eager to make it, now I'm eager to stay where I am, and eagerness is everything to my tennis."

Conspicuous by its absence is the entourage that used to follow Connors in the Riordan days and beyond, like so many handlers coddling and fawning over a prizefighter. There was his mother Gloria; Coach Pancho Segura, and a collection of go-fers, body guards, camp-followers and hangers-on.

So far this year, Connors has won the Masters over arch-rival Bjorn Borg, finished as runner-up to borg in the four-man "Pepsi Grand Slam" at Boca Raton, Fla., and won at Philadelphia, amassing $199,000 in prize money for January.All the while he has traveled alone, or with one favored "walking-around guy," Lornie Kuhle of Los Angeles.

"look around" he said at Philadelphia. "Dibbs has a friends with him from Miami. Harold Solomon has his girlfriend. Lots of guys have their wives. It's probably necessary - to have somebody you can talk to and relax with.