Bob Lutz and Stan Smith have been a fixture in United States Davis Cup competition for the past 13 years. But Lutz admitted today that, at one point, he had his doubts about the Cup quarterfinals here.

"At first, I wasn't sure I wanted to play, to be truthful," Lutz said after he and Smith defeated Ivan Lendel and Tomas Smid, 9-7, 6-3, 6-2, at the National Tennis Center to give the U.S. a 2-1 lead in the best-of-five-match series.

Lutz was upset because he "thought we had a verbal agreement" with Captain Arthur Ashe from the start to play against Czechoslovakia. But Ashe actually chose Gene and Sandy Mayer. Lutz and Smith were named only when Gene Mayer injured his wrist at the French Open last month.

"I wasn't sure what Arthur's reasoning was for using the Mayers in the first place," said Lutz. "He had pressure from different parties and, also, the Mayers are from New York. I was a little iritated because we had a good record and I had planned my schedule six months in advance."

"I enjoy playing Davis Cup. This is the first time in a long while it's been in New York and it's a big match," Lutz went on.

Smith said he didn't feel as strongly as Lutz about what he called a "communication problem," but confessed that, "Arthur didn't handle it as well as I had hoped."

Assuming the United States, needing only a victory from either John McEnroe or Jimmy Connors, defeats Czechoslovakia Sunday, it will advance to the Davis Cup semifinals, against either Australia or Sweden, in October. Ashe will again have to decide between McEnroe-Peter Fleming (the top-ranked doubles team in the world), Smith-Lutz and Mayer-Mayer in the doubles. Choosing either of the latter two teams would allow McEnroe to concentrate on singles, as he is doing here.

"I hope Arthur stays with our team the rest of the year," said Smith, who won the 1980 U.S. Open doubles title and reached the finals at Wimbledon last week with Lutz (before losing to McEnroe and Fleming). "We're playing well and it's a good format to have a fresh doubles team."

On the international circuit, Smith, 34, and Lutz, who will be 34 next month, still consider singles their primary concern. Fans often dismiss them as "over the hill," but their recent singles performances suggest that those opinions might be a bit premature.

Lutz, ranked No. 23 in the world in singles, was named Tennis magazine's comeback player of the year in 1980. After his ranking dropped to 52nd in July, Lutz won two consecutive tournaments for the first time as a professional, later added a third title and reached the semifinals in three events.

"It wasn't any one thing," Lutz said, explaining his resurgence. "I was working hard, nothing happened, and finally I guess it paid off. I just went back to basics. I was trying to experiment a little too much."

Smith, who won the singles title at Wimbledon in 1972, reached the round of 16 there this year before losing to McEnroe in four sets.

"I played well the whole tournament, especially against McEnroe," Smith said. "I won the second set and had breaks in the third and fourth, but McEnroe started playing really well and I lost the match."