Unless the Washington Diplomats "show some signs of growth and progress" by the end of the 1980 soccer season, the team probably will be moved or sold, David (Sonny) Werblin, president of Madison Square Garden, said yesterday.

"If there is no growth by the end of two seasons for us with the club (the Garden purchased the Dips last October) then we'd have to sit down and seriously think about moving," Werblin said. "I don't mean that as an ultimatum or anything, it's just common sense.

"This is no different from any other business. If you set up shop on the wrong corner you move to another corner."

Werblin said he had hoped the Dips would average 18,000 fans per home game this season (the team has averaged slightly fewer than 11,000 for nine home dates).

"I haven't seen any evidence of growth thus far," he said. "Maybe in July when we come back from our West Coast trip we'll see some. But not yet."

Although attendance this year is about the same as 1978, Werblin's assistant, Jack Krumpe, pointed out recently that ticket sales have doubled.

Werblin, interviewed prior to the Diplomats' 2-1 win over Philadelphia at RFK Stadium yesterday said he was disappointed by the fans' reaction to the team this season.

"We've been stymied by a combination of the Bullets and the weather, I know that, "Werblin said. "I mean they are like a buzzsaw together. But it's been frustrating, not so much for me as the others working to try and find the market around here.

"Look, I don't want to sound like Bob Short (former owner of the Washington Senators) and start scolding the fans but I wonder if there is a Washington.

"Your main Washington people are not here in town on weekends. Your newsmakers get out of town. Sure they come to Redskins' games but that's it. Today we're playing Philadelphia. You would think that maybe a senator or congressman from Pennsylvania would be here. They were invited.

"I think people like that are important. They make news and we need to do that. I've always maintained that you sell sports as much on the news pages as on the sports pages." Asked why the Dips have failed to purchase any big name stars to try and improve the gate, Werblin said they had tried during the offseason then backed off later.

"We tried to get (Kevin) Keegan (from England) and we still have a commitment from him to come here if the rules problem can ever be worked out and he becomes available," Werblin said. "We also tried to get (Daniel) Passarella (from Argentina). But what he was asking for from what we saw of him as a player, he just wasn't worth it."

Since the NASL season began, several foreign stars, including Dutch World Cup star Johan Cruyff, have come into the league, none ot the Dips. "Frankly, at the time when Cruyff was available we hadn't seen any indication that Washington was accepting the Diplomats or that it is doing so now." Werblin said.

"We have a very representative team," Werblin said. "If we had caught a couple breaks we would be in first place. But we haven't found a way to get the community really interested yet.

"I don't know what he answer is. If I did I would be doing it. It might be that there is no answer. I prefer to think that it's something that we're not doing yet and eventually we'll find out what it is."

Werblin also conceded that the Dips probably would be playing in New York's Shea Stadium if the Cosmos had not demanded a reported $12 million indemnity fee in return for letting Gulf and Western - which owns the Garden - into the New York area.

"I don't think the New York thing can be worked out because of the Cosmos," Werblin said. "If we feel things are not working here we could move the team or we could just abandon the project and sell."

The 24-team NASL also is a major concern, Werblin said. "I'd rather see us have eight teams," he said. "Have a team in Boston, one in New Jersey, and one in Washington.

"Build up the rivalries that way. The way they have it set up now, two guys have a fight in a game and they don't see each otherfor a year. The fans can't identify with that. Let's give them some excitement and give the press something more to write about.

"Now, our guys leave on an eight-day trip all over the country on Thursday. That's just disastrous. I mean this system is great for the airlines, but that's about it."

While Garden management is clearly taking a wait and see approach to the Diplomats, Werblin said it was trying extremely hard to find the right answers for the current problems.

"I'm not discouraged," he said. "I think the reaction by the fans who are coming has been excellent. I think if we were playing in a smaller stadium, say about 30,000, things would be more exciting.

"I've talked to the governor of Virginia (John N. Dalton) to see about the possibility of some kind of a stadium in Alexandria. He was enthusiastic, but we really haven't gone beyond the social talking stage.

"We didn't come here to experiment. We came here to try and set up a permanent franchise. We've worked very hard and spent a lot of money on our marketing effort.

"We will definitely be here next season and we're going to keep working to find the answer.We don't have a dull team so we don't need wholesale moves. I see the big crowds in Minnesota, Vancouver, and Tampa and I can't understand it. Where are all the people? We have to find that out." CAPTION: Picture 1, Fury goalie Keith Van Eron closes eyes and appears to shy away from onrushing Diplomat striker Paul Cannell, who tormented the keeper from the start and victimized him for two goals in Washington's 2-1 victory at RFK Stadium.By Lucian Perkins - The Washington Post; Picture 2, Sonny Werblin