North American Soccer League Commissioner Phil Woosnam said yesterday that he considers Washington one of the league's most important cities, adding that he expects the league to have a team in Washington "for a long, long time."

Woosnam, attending a luncheon at RFK Stadium, said, "Washington, New York and Los Angeles are the key cities for us if we want to gain international acceptance.

"I think the franchise here is ready to take off in the next couple of years. They've established credibility here, now they have to take advantage of it."

Woosnam's optimistic words were in direct contrast to those of Madison Square Garden President Sonny Werblin. (The Garden purchased the Dips last October). He said on June 24 that the Dips' new owners were "disappointed by the lack of growth" in soccer interest in the area. He added that if the Dips did not show signs of growth by the end of 1980 season, the team probably would be moved or sold.

"I'm not sure what Sonny was thinking about when he said those things," Woosnam said. "My personal feeling is that Washington has come a long way to get where it is today."

The Dips appear to be in position to draw their largest non-Cosmos crowd even for Sunday's 2:30 p.m. game with Johan Cruyff and the Los Agenesl Aztecs. Just before the close of business yesterday, the advance sale for the game was about 18,000, according to General Manager John Carbray.

"The crowds will come," Woosnam insisted. " they are going to come here and they are going to come in cities around the league.The teams that aren't doing well have to learn from the teams that are doing well."

Woosnam, 46, is an optimistic fellow with two dreams for American soccer; full stadiums by 1985 and the World Cup in 1986.

"I think we're ready to have the World Cup in this country," Woosnam said. "The interest is here in a lot of areas and if they announced tomorrow that the World Cup would be played here it would cause the whole soccer thing to take right off.

"Sports are about credibility and for soccer the ultimate in credibility is the World Cup."

Woosnam also predicted that the NASL would be playing to sellout houses on a fulltime basis by 1985.

"We've achieved credibility now, which four years ago before Pele we didn't have. Now we have it. If we do everything right the next few years, build on our strengths, we'll have every stadium in this league full by 1985, he said.

Asked what weaknesses he saw in the league, Woosnam said, "Well I suppose the large differential in attendance between some clubs is a problem. And the differences in financial stability between some clubs is also something that is less than ideal.

"But," he added quickly, "I expect the gap to close in the near future."

Woodnam said he expected the league to remain essentially the same next season. Yet, with Memphis owner Harry Mangurian looking to sell his team and Philadelphia and Portland apparently on shaky ground, he conceded there could be changes.

He also defended the league's expansion two years ago from 18 to 24 teams, a move which has produced one franchise shift, four shaky franchises and one good franchise (Detroit) thus far.

"Almost all expansion teams run into some problems at the outset," he said. "We felt 24 was an ideal number for us in terms of competition so we made the move."

Woosnam also engaged in a lively discussion with Carbray over the July 15 game between the Cosmos and Vancouver in which four players, including Giorgio Chinaglia of the Cosmos were ejected. When the referee showed Chinaglia the red card, Chinaglia snatched it from his hand and threw it on the ground.

Last season, Washington's Mike Dillon jostled a referee in Dallas after being red-carded and received a six-game suspension.

"The difference is contact and noncontact," Woosnam said. "Dillon jostled the referee. What Chinaglia did showed disrespect but so does cursing and we can't control that unless we put a tape on the referee, can we?"

"tbut now, you're saying that any player who is red-carded can do that," Carbray said. "In effect, you've said it's okay to do that."

"On the next one I might order a suspension," Woosnam replied.

"But that isn't fair," said Carbray. "How can you suspend one but not another?"

"All depends on circumstances," said Woosnam, adding, "I try very hard to be fair but since we're located in New York, people always think we're prejudiced toward the New York team like in other sports. But it isn't true."