NEW YORK, SEPT. 8 -- The most anticipated match of the U.S. Open, the quarterfinal between John McEnroe and Ivan Lendl, will be played Wednesday night. The U.S. Tennis Association decided to schedule the match at night to accommodate USA cable television even though both McEnroe and Lendl have played at night and Jimmy Connors and Brad Gilbert, Wednesday's other men's quarterfinalists, have not.

It has been an unwritten rule at this tournament dating back to the days when Bjorn Borg tried to get out of playing at night, that all seeds would play at least once at night if they reached the quarterfinals.

Throughout this tournament, the night schedules have been much more attractive than the day schedules, partly because of complaints about weak night programs last year and partly, according to tournament referee Gayle Bradshaw, to accommodate USA.

The scheduling of so many night matches -- especially singles matches that begin after 9 p.m. -- has meant that many spectators leave well before the end of the matches. That leaves the players to play in front of almost empty stadiums until ludicrous hours (Gabriela Sabatini finished one match at 1:19 a.m.).

Lendl and McEnroe have not played a Grand Prix match to conclusion since the final here in 1985. Last month, they met in a final at Stratton Mountain, Vt., but were rained out with McEnroe leading, 7-6, 1-4. Lendl won the '85 final in straight sets and displaced McEnroe as the No. 1 player in the world with that victory. He has been there ever since; McEnroe has slid to ninth on the computer.

McEnroe has said throughout this tournament that he would love another chance at Lendl. He has made no secret of his disdain for him and has said Lendl being No. 1 has hurt tennis.

Something you can expect to see sometime in the future: Boris Becker and Steffi Graf playing mixed doubles together. It is a natural to pair the two West German teen-agers, not so much to win matches but for fan appeal and money.

One source said today that if Becker and Graf were paired to play a mixed doubles exhibition in West Germany, they could easily split $250,000 a night. If the pairing worked, they might then consider playing together in Grand Slam tournaments, especially if Graf and Gabriela Sabatini break up as a women's doubles team after this year as has been speculated . . .

Lendl, when asked if he had watched the McEnroe-Slobodan Zivojinovic debacle: "Yes, I saw a little of it between periods of the hockey game."