NEW YORK, AUG. 30 -- Andre Agassi has his hot clothes and Ivan Lendl has his hat. It is a foreign legion model with a cloth tail that protects his neck from the sun, and it is becoming Lendl's signature at the U.S. Open.

Lendl gets the hats from Australia. His coach, Australian Tony Roche, brought a new supply in for the tournament. Lendl said he has gotten letters from health groups and the American Cancer Society telling him the hat will save his strength and protect him from the more damaging rays of the sun. Lendl likes it so much he has asked his clothing company, Mizuno, to manufacture his own model.

"I've had a lot of requests," he said. "Even though it may look a little bit funny, I feel that the hat, especially the cloth on the back, saves you a lot of energy. I tested it a couple of times in Australia to see how long I can maintain playing at a certain level, and I think with the hat you can play 20 to 30 percent longer without tiring.

"I've gotten more than a few letters from groups saying they wish more people would wear something to protect the head. That's why I wear it, to save energy and protect me from the sun." Three-Decade Player

During a little more than six months on the tour, Jennifer Capriati has had many doubles partners. In her debut tournament, the Virginia Slims of Florida, she played with 46-year-old Billie Jean King. At the Italian Open she teamed with "The Ledge," 33-year-old Martina Navratilova. Here her partner is 19-year-old Meredith McGrath. If she can find a teammate in her twenties, Capriati will have spanned four decades. . . .

Steffi Graf and Gabriela Sabatini are not entered together in the doubles and apparently have ended their partnership. The team of young prodigies, Graf, 21, and Sabatini, 20, has been a unit in Grand Slam events since 1986. Sabatini said she wants to play several more events in doubles than just the majors, feeling that would improve her game. Graf is teaming with Lori McNeil here; Sabatini is seeking a new partner. . . . Typical New Yawk

Navratilova was informed by U.S. Tennis Association officials that her water bottle was not "neat" enough. Navratilova had taped over an insignia on the bottle at their request, and then was told that it wasn't tidy.

"So I put it in a brown paper bag," she said. "I figure they're used to that in New York."

Navratilova has a bone to pick with Vitas Gerulaitis, who is doing analysis on USA Network, and, according to her, running down women's tennis, which he considers boring. "It's embarrassing," she said. . . .

Wild-card Patrick McEnroe reached the second round of a Grand Slam event for the first time in his career. The younger brother of four-time champion John McEnroe defeated Jeff Tarango in five sets on Wednesday, 6-3, 6-4, 1-6, 2-6, 7-5.

"I think he's done well for himself in a difficult situation," John said.

It got more difficult today. Patrick fell to Christo van Rensburg, 6-4, 6-4, 7-5. Of Minors and a Major

Monica Seles, 16, said she supports the Women's Tennis Association rule that prohibits girls under 14 from playing professionally -- even though it held her back. Of the increasingly younger players on tour, she said: "I don't know if it's good or not, but what are you going to do when you're playing so well? I don't know what age it will end. Maybe in a few years you'll see a 10-year-old."

Seles is uncommonly articulate in English, but every once in a while betrays her Yugoslavian origins. Today she wanted to thank the mayor of New York, David Dinkins, for rerouting the planes from LaGuardia Airport so they do not fly over the National Tennis Center. Only, she referred to him as "Major Dinkinson."