Barring a snag in the next few days, there will be professional soccer in Washington in 1981, informed sources said last night.

Following a series of meetings with potential local investors yesterday, Duncan Hill, Detroit Express general partner, said he was very encouraged by the meetings and indicated he thought the chances of the Express moving to RFK Stadium were good.

"Our meetings today went very well," said Hill, who would not reveal the names of the investors. "Since I arrived more people have come forward and expressed interest so I'll be meeting with them during the next couple of days. Right now, we're very interested in Washington."

Hill and his partners are more than interested, sources said last night. "Right now, the chances are much better than 50 percent that the team will be moved," one league source said last night. "They want out of Detroit."

Hill was careful to point out that even if the Detroit ownership decided to move the club, the league would have to give approval. Phil Woosnam, North American Soccer League commissioner, already has indicated he wants a team in Washington this season and league owners, who were shocked when the Washington Diplomats folded in November, undoubtedly would back the move.

Hill also met yesterday with Gordon Bradley, coach of the Diplomats, and Robert Sigholtz, general manager of the D.C. Armory Board. Hill and Bradley discussed Washington as a soccer market. Although neither man will comment, Bradley likely would coach the team if it moves here.

Hill's meeting with Sigholtz was to discuss a lease. A lease for RFK Stadium would cost the Express a good deal less than their current lease in the Pontiac Silverdone. The Express averaged about 11,000 fans per game there last season -- compared with the Diplomat's 19,205 -- and would not have difficult time getting out their lease in Pontiac, according to sources.

Although this venture started as a simple buyout of the Detroit owners by the Washington investors, it now seems likely that Hill and his partners will move here even if a deal falls through, sources said.

Last night, Hill talked like a man who wants his soccer team here. "Nothing's been decided, but we're certainly pleased with the response we've gotten here," he said. "This is a delicate time right now."

Bradley, after meeting with Hill, was optimistic. "I think they like just about everything about Washington," Bradley said. "One way or the other, I expect something to happen the next couple of days."

Hill said he plans to stay here through Friday. About the only thing that could stop the move now would be a sudden backing off by the Washington investors or time being too short to make the move. But those problems are considered relatively minor.

The Express record was 14-18 last season and recently the team unloaded its two top players in order to save money. "We do have a cash-flow problem," Gerritt B. Lemmen, one of Hill's partners said. "That's why getting some help from investors in Washington and putting the team in a place where the economy isn't depressed like Detroit would definitely be helpful."

The 1981 soccer season -- with or without Washington -- opens four weeks from Saturday.