The Washington Diplomat franchise expired yesterday but North American Soccer League owners left the door open for a revival Sunday of the team president, Steve Danzansky, can put together a group to whom league owners will grant a franchise.

"The team has been terminated, but it's conditional," Danzansky said. "We've still got a chance."

That chance lies in Madison Square Garden Corp.'s agreeing not to do anything with any of the player contracts for one week. The Garden voluntarily terminated the franchise yesterday but said it would not do anything with the contracts of the players and would be willing to sell the contracts to a new owner if one can be found.

At the same time, the contract of Johan Cruyff reverted to the Cosmos under terms of the deal that brought the Dutch superstar to Washington last February.But Cosmos officials told Danzansky they would be willing to listen to offers for Cruyff from any new Washington owners.

The league also terminated the Rochester and Houston franchises yesterday but told groups from those two cities that they could also make presentations to the league executive committee when it meets in Chicago Sunday.

"We would have to issue all three new franchises at this point," Commissioner Phil Woosnam said. "Right now, all three are terminated."

It was Woosnam who kept Washington's last-ditch hopes alive yesterday. During a 2 1/2-hour conference call with league owners, he argued strongly that the league should wait at least until next Monday before going ahead with plans for a 21-team league in 1981.

"There were a lot of owners hostile to the idea of allowing this to continue any further," Danzansky said. "Their attitude was the Garden had a chance to sell, didn't and that was the end of it. But Phil and I both pointed out that it wasn't the Garden we were asking extra time for but the city of Washington."

Because MSG had voluntarily terminated the franchise, owners could not vote to grant an extension in the life of the current Diplomat organization. Instead, they voted to give Danzansky a chance to revive them with a new franchise certificate Sunday.

Danzansky said he now plans to get back in touch with the people who have expressed interest in the franchise to see if they are still interested. Any new owner would have to do three things to keep the Dips in business in the same way they operated in 1980: they would have to convince the league to grant them a franchise; negotiate with MSG for purchase of the player contracts, and negotiate with the Cosmos for Cruyff's contract.

Woosnam will be in Washington again today to talk to potential buyers. "I want badly for Washington to have a franchise, I've made that clear," Woosnam said."I think potentially this could be the best franchise in the league. The groundwork has been laid."

Jack Krumpe, Madison Square Garden executive vice president who represented the corporation during the conference call, said that MSG was still hoping Washington will have a team next year.

A last-ditch effort by a Vietnam veterans group to get an injunction against the league to keep it from terminating the team was turned down by a D.C. Superior Court judge yesterday.