On the Surface, U.S. Staking Its Chances on Experience : * Davis Cup: McEnroe heads an American team that is missing its best young singles players. The quarterfinal matchup against Spain will be played on grass.

The present and future kings of American tennis, alive and well and bagging titles around the world, are noticeably absent for the weekend’s goings-on at this stately shrine to their forebears.

Beginning today, John McEnroe and Brad Gilbert, who both passed from tennis’ cutting edge some years ago, will compete in the singles matches against Spain on the tradition-rich grass courts of the Newport Casino and International Tennis Hall of Fame. Veterans Jim Pugh and Rick Leach, undefeated in Davis Cup action, play the doubles match Saturday, between two days of singles.

“This is one of the oldest teams we’ve had in a while,” said Tom Gorman, captain of the U.S. team. “They’re all veterans this time.”

The young lions, newly crowned French Open winner Jim Courier, fellow French finalist Andre Agassi and U.S. Open champion Pete Sampras, have left their more grizzled and lower-ranked counterparts to carry the Davis Cup torch against the Spaniards, who are known neither for their expertise on grass nor their Davis Cup history but do have the services of Emilio Sanchez, their best all-around player who ranks 12th in the world.

McEnroe, America’s all-time leader in Davis Cup victories, has been questioning the younger players’ priorities during practice here and Thursday said he was worried about the future of America’s commitment to Davis Cup competition.

“I feel concern about it,” McEnroe, 32, said at a news conference after the draw had determined that he will play Davis Cup rookie Tomas Carbonell today after Gilbert, 29, plays Sanchez. “I don’t understand why they’re making that decision.

“I think it’s important because you come together as a team, there’s a real feeling that really helps. (On the tour,) players feel very isolated. Everyone’s separated from each other. (Davis Cup) gives people an opportunity to get together.

“Whoever’s telling Sampras (a fast-court specialist) that he shouldn’t play Davis Cup, I just don’t understand. It doesn’t make sense that a guy like Sampras would be unavailable for this match.”

Said Gorman: “There’s no law, they can do whatever they want. (But) I’m always personally very disappointed when anybody says no. It always surprises me and maybe even shocks me--doesn’t shock me as much because it’s gone on two or three years, but I don’t understand it at all.”

As Gorman called around, most of the younger players told him they couldn’t commit to the Davis Cup because of its timing--between the French Open and Wimbledon. But Gorman said he thought playing at Newport was the perfect lead-in to Wimbledon’s grass courts.

Because of those absences, the Americans and Spaniards concede that Spain’s best chance at breaking through is for Sanchez to beat Gilbert, ranked No. 17, in today’s first match, giving the rest of the team the confidence to carry out an upset run.

Sanchez, who lost to McEnroe in a memorable four-set match at last year’s U.S. Open, also is anchoring Spain’s doubles team, playing with doubles specialist Sergio Casal, and has been handed the kind of burden McEnroe used to carry in his prime.

“I hope I have enough gasoline to go all the way in the matches,” Sanchez said. “Maybe we don’t have a big chance on paper, but on this surface, matches are usually really close, and I hope I can take advantage of the breaks.”

“He’s one of the fittest guys on the tour,” McEnroe said. “(Playing all three days) may affect him a little . . . (But) I see him in the majors play in mixed doubles, doubles, men’s singles. He’d play in juniors if they’d let him in.

“So he’s the type of guy that plays better when he plays a lot. So it’s not necessarily a negative. He seems to go for a long time.”

If Sanchez, 26, can beat Gilbert, Carbonell, 22, won’t have the pressure of having to beat McEnroe in his Davis Cup debut, and the strong team of Sanchez and Casal would have a shot at pushing Spain up, 2-1, on Saturday.

“They have a tremendous doubles team,” Gorman said. “This is the most difficult doubles team that the United States is playing in at least six or seven years in Davis Cup.”

Sanchez said that he and Casal have played the Leach-Pugh team “three or four” times and have lost each time.

“But I think here is different,” Sanchez said. “In Davis Cup, we usually play much better.”

Carbonell, for his part, sounded very much like the 70th-rated player he is, willing to whale away and see what happens against McEnroe.

“I feel so happy about the decision,” said Carbonell, who found a spot on the team when No. 6-rated Sergi Bruguera had to bow out because of a back injury that forced him miss the French Open.

“I know it’s tough to play first time against the States, Davis Cup, against McEnroe on grass, which is not my best surface,” Carbonell said.

“I know no one expects it, but I hope to give some surprises. I have nothing to lose, so I’m just going to go for it. It’s the only chance I have to win the match.”

Davis Cup Notes

The winner of this quarterfinal round match advances to play Germany, which beat Argentina, in the semifinals. . . . John McEnroe last played here 14 years ago. “Yeah, every 14 years I play here,” he said. “In another 14 years, I’ll come here as the trainer. In another 28, I’ll be the captain.”

Spain captain Manuel Orantes said playing on grass shouldn’t cause his players to believe they can’t win: “It’s all in your head. If the other guy doesn’t play, we’ll be there.” . . . Singles players will trade opponents Sunday, McEnroe starting off against Emilio Sanchez and Brad Gilbert scheduled to play Tomas Carbonell.

INSIDE THE DAVIS CUP

What is it? Begun in 1900 as a men’s team competition between the United States and Great Britain, it has grown into an annual event involving countries from around the world.

The format: Competition is divided into the World Group and various zones. The countries in the zonal, or regional, competitions are playing to qualify for the next year’s World Group; the 16 countries in the World Group are playing to win the Davis Cup.

Getting into the World Group: The eight teams in the World Group that win their first-round matches will remain in the World Group the next year. The eight teams that lose those first-round matches must enter a playoff round against the eight finalists of the top four zonal competitions. The winners qualify for the World Group the next year; the eight losers drop back to zonal competition.

The teams: Each country has two singles players and one doubles team. Matches are best of five sets, with tiebreakers in the first four sets, but no tiebreaker if a fifth set is required. The first team to win three matches is the winner.

This weekend’s competition: The United States and Spain are playing in the second round of World Group play at Newport, R.I. John McEnroe and Brad Gilbert will play singles and Rick Leach and Jim Pugh doubles for the Unites States. Emilio Sanchez and Francisco Clavet will play singles and Sergio Casal and Tomas Carbonell doubles for Spain. Two singles matches will be played today, the doubles match Saturday and two more singles matches Sunday. The playing surface is grass.

How they got there: In the first round, the United States defeated Mexico, 3-2; Spain defeated Canada, 4-1. If the United States advances, it will play host in the semifinals to Germany Sept. 20-22. The finals will be Nov. 29-Dec. 1. The United States is the defending champion.

DAVIS CUP CHAMPIONSHIPS United States....29 Australia........26 Great Britain.....9 France............6 Sweden............4 Germany...........2 India.............1 Czechoslovakia....1 Italy.............1