Duncan Hill, an owner and the general manager of the Diplomats, has left Washington and returned to Europe, according to sources close to the North American Soccer League team.

Hill apparently has abandoned the franchise two days before its scheduled termination. Unless it is sold by Sunday, the debt-ridden club will become Washington's second professional soccer team to fold within one year.

Several sources within the franchise confirmed yesterday that Hill had moved out of his Springfield townhouse earlier this week and left with his wife and baby daughter for England.

Diplomat Coach Ken Furphy, in Toronto for Saturday's Soccer Bowl between Chicago and the Cosmos, said yesterday he is negotiating contracts for some of the Washington players, including goalkeeper Jimmy Brown.

Duncan Hill and his father, Jimmy, the majority owner who is now doing soccer broadcasts in England, lost at least $1 million this season and face debts of up to $1.7 million in Washington and Detroit, where the franchise was based from 1977 to 1980.

It also was learned that Duncan Hill has filed a grievance with the NASL Players Association, contending that Dutch superstar Johan Cruyff should have to return part of his $175,000 half-year salary for allegedly misleading the club about his health.

Hill worked a surprising deal to bring Cruyff back to Washington on July 1, less than two months after Cruyff had a groin operation. Hill insisted he knew of Cruyff's condition at the time, but complained at the end of the season after Cruyff played only three entire games and the team failed to make the playoffs. Cruyff has returned to Holland and could not be reached for comment last night.

NASL Commissioner Phil Woosnam seemed surprised when he learned from a reporter yesterday that Hill had apparently left the country. "That's the first I heard of it," Woosnam said. "That's news to me. I don't know what to say. I'm just not qualified to make any statement until I learn more."

Woosnam has said there is little chance an expansion team will come into Washington next season. Franchises in Atlanta, California and Dallas already have folded, and the league will hold a dispersal draft on Oct. 6 for the Atlanta and California teams. Dallas owner Lamar Hunt has worked out an arrangement with the Tampa Bay Rowdies in which the Rowdies will absorb the Dallas roster.

The Calgary franchise, which was pronounced terminated more than a week ago, has been saved by a new investor, Otto Knipschild, who will post the required $150,000 performance bond but is still subject to league approval.

On Sept. 16, one day after the Diplomat management did not meet the performance bond deadline, Woosnam gave Duncan Hill an extra 11 days to sell the club. But no buyer has materialized.

The final fate of the Diplomats will be decided in a league meeting beginning Sunday in Toronto.