Howard Samuels, the chief operating officer of the North American Soccer League, said yesterday he expects a NASL franchise in Washington by 1984, even if another city is picked as the home base for Team America.

"I am convinced whether or not the World Cup team comes to Washington, I'm telling you there will be a team in Washington by 1984 . . . It's a natural market," Samuels said in a telephone interview after returning from league meetings in San Jose, Calif., at which the Team America concept was approved.

Washington has been without major league soccer since 1981, when the Diplomats franchise folded, the second team to go under in two years. Samuels said the owner of at least one existing NASL franchise, whom he declined to name, has shown interest in moving here if Team America is not based in Washington.

Bob Sigholtz, manager of the D.C. Armory Board, which has jurisdiction over RFK Stadium, said he has been talking with NASL officials for the past three months. Samuels has had discussions with Joseph H. Riley, president of the Greater Washington Sports Authority, about possible local financing and sponsors. But sources said no one in this area has made a commitment.

Now that the Colombian government has said it will not be able to host the 1986 World Cup matches, Samuels predicted the U.S. Soccer Federation "will make a major effort to get the World Cup here." Brazil and the United States are expected to be the top choices to replace Colombia.

Samuels, an unsuccessful candidate for governor of New York and the man who put together the state's Off-Track Betting system, was hired by the NASL three months ago to put together a plan to make professional soccer a profitable business in this country. League members lost $25 million last year and only 12 franchises remain, down from 24 in 1980.

The Team America concept, credited to NASL Commissioner Phil Woosnam, is seen as a three-tier developmental program for youth, Olympic and World Cup competition. It is the centerpiece of Samuels' marketing approach. Team America is a joint venture of the NASL and the USSF, with the team initially being stocked with U.S. players on loan from the league's franchises.

The cost of Team America would be $4 million initially, with national sponsors contributing most of the funding. Samuels said some league owners want to have a group of NASL owners "put money up and own the team ourselves."

Samuels said he and owners in the league favor Washington as the home base for Team America, and that former Diplomats coach Gordon Bradley would be considered for a management position. The coach is named by the USSF; Bradley is a former interim coach of the U.S. national team.

The obstacle to Washington's being almost certainly the home for Team America is Denny Long, the president of Anheuser-Busch Inc., of St. Louis. He is a big soccer fan and is pushing for his company to be the team's primary corporate sponsor. If that happens, there is a strong possibility that firm would want the team based in St. Louis. Samuels said he is scheduled to meet with Long Thursday in New York.

Because of time considerations, Samuels said, there is less than a 50 percent chance Team America could be ready for the 1983 season, which starts April 27. The deal must be finished in six weeks, he said, and many major corporations do not make advertising decisions that quickly. He said Team America was 90 percent certain for 1984.

The main parts of Samuels' plan to stabilize the NASL:

* Create new excitement by stepping up Americanization of the league. That includes Team America and an emphasis on youth soccer. To Samuels, the lack of native-born players to serve as examples for U.S. youth is a major problem facing the NASL.

* Play league competition both indoors and outdoors in the nation's major markets. "No team can make money on outdoor soccer alone," Samuels said. He also said the league needs national television contracts to succeed and he sees cable TV playing a major role to that end in three to five years.

* Share gate receipts, as the National Football League does. This idea "is a couple of years away," Samuels said, but necessary for economic survival and competitive parity.

In other developments involving soccer:

* Sigholtz said the Armory Board has been told that it will play host to six soccer games in the 1984 Olympics. No other details, such as group or round, are known, he said. The semifinals and final are scheduled for the West Coast.

* Samuels said Bernie Rodin, owner of the Baltimore Blast, a successful team in the Major Indoor Soccer League, has indicated he wants to join the NASL in 1984. Samuels said Rodin also told him he welcomed franchises in the Washington and Baltimore markets as creating "a natural rivalry."