Last fall, as Armani premiered its collection of sporting pants and sweaters in Milan, Andre Agassi offered a glimpse of his own impending make-over. His shirt and hat were printed with rude phrases slamming tennis. Once Nike made the outfit available in stores, he quit wearing it. Mr. Agassi refuses to look like everyone else, a company spokeswoman explained. So in January he unveiled a newer, more shocking incarnation, a streetwise array of stripes and prints and knee-length baggies. To go with the look, Mr. Agassi sheared his trademark hair to stubble, with sideburns, and wore thick hoops in each ear. "I can get ready now in about 6 1/2 minutes," he said. "Believe it or not, that was all that was behind it." London tabloids, which seemingly never tire of discussing him, guessed otherwise. The hair was a ploy by Nike, or perhaps the influence of new girlfriend Brooke Shields. At the very least, they suspected, it was a publicity stunt. After all, this was an athlete known as much for style as for his thunderous forehand. His surge to the top of the world rankings belies a single-mindedness, but he long ago confessed to keeping one eye on the crowd. "There's different things about me that people like. It's not just watching me win," he said in 1989. "They don't know what's going to come out of me, whether I'm going to lose my mind or laugh." With its crisp whites and classic lines, tennis is undoubtedly a stylish sport. By the same token, it resists the tides of fashion. The men's game, in particular, clings to a code of decorum. Mr. Agassi, 24, represents an anomaly if only because he has dragged the outside world, kicking and screaming, into these quiet confines. He told Tom Tebbutt of the Toronto Globe and Mail that he wanted the new collection to be "something that guys could wear skateboarding." Thus the retro gingham, the oversized shorts. "It is supposed to be ugly," explained Devon Burt, Nike's creative director of apparel. "The whole philosophy" was to rattle people. At the same time, his clothes might be garnering favor with non-tennis fans, with the kids who are shopping for Stussy and Mossimo. "The Mr. Tough Guy tennis look," David Letterman called it when Mr. Agassi appeared on his show recently. "It's certainly not Lacoste," Kevin Stewart, fashion editor at Vibe magazine, agreed. "A lot of those printed tops of his can be worn on the street." Something different But Nike designers had something very different in mind when they set to work on the collection in the summer of 1993. That was the summer Mr. Agassi made the transition from tennis star to pop icon. He wore fluorescent bicycle shorts and hair down past his shoulders. After each match, girls shrieked as he tossed his sweaty shirt into the crowd and the paparazzi waited in hopes of spotting him with Barbra Streisand. It was no accident that the public identified Mr. Agassi with a slogan more befitting a fashion figure: "Image is everything." Still, Nike executives fretted. Flying to meet with him at a tournament in Cincinnati, they suggested a change. "Sometimes worry about who's going to wear this stuff," Mr. Burt said. "We worry there's only one person in the world who can get away with it and that's Andre." In a typical response, Mr. Agassi scoffed. "He said, 'You're boring me.' " That a multimillion-dollar corporation would follow the instincts of its rebellious poster boy should come as no surprise. Launched as a running-shoe manufacturer, Nike entered the tennis market in 1973. Pitted against established designers such as Adidas and Fila, the Beaverton, Ore., company sought to make a little noise by paying Ilie Nastase, then the brashest player on the tour, to wear its clothes. Later, John McEnroe joined the fold. Combining the mouth and the talent, he cemented Nike's position among the top tennis designers. But the company was making far more waves on the basketball court with black Air Jordans and in football with Bo Jackson. Its tennis line took a back seat. All that changed when executives noticed a precocious 13-year-old on the junior circuit. "He was the kid with the flair," a Nike spokeswoman said. "He had charm. And he always had a weird hairdo and a ripped bedsheet as a bandanna." Mr. McEnroe was fading by that time. A staid Ivan Lendl ruled tennis. In 1986, the teen-ager arrived with his rock 'n' roll hair. "Andre was the new 'anti'-player," said Mary Carillo, who comments on the game for ESPN. "He shook everything up." The rumbling grew louder in 1988, when Mr. Agassi stepped on court in denim-look shorts. Not since Gussie Moran flashed lace panties at Wimbledon in 1949 had tennis suffered such an indiscretion. Officials consulted their rule books. The shorts were actually Mr. McEnroe's idea. He suggested them to Nike designers but balked upon seeing the finished product. Mr. Agassi gladly stepped in. In on the decisions From then on, Mr. Agassi participated in every decision when it came to the clothes he wore, meeting with Nike throughout the design of each new collection. Some people loved his look, others hated it. Either way, he was all the buzz. "Andre has always felt that it is his position to make tennis a little more exciting," Mr. Burt said. "He has always been willing to take chances with his appearance." The next temblor struck at the U.S. Open in 1990. While Nike's other top players, Pete Sampras and Jim Courier, dressed conservatively, Mr. Agassi showed up in lime bicycle shorts with a black, white and lime shirt and a headband. "Looks like he missed the train to Woodstock," Mr. Blackwell told Tennis magazine. The French Open threatened to impose an all-white-clothing rule. At Wimbledon, an official vowed never to allow anyone "so scruffy" onto the grounds. Mr. Agassi had exceeded the bounds of sport. For better or for worse, he was a fashion icon. C7 "If you think this is bad," he teased, "just wait."