The National Labor Relations Board will seek a temporary restraining order in federal district court in New York today that would postpone the major league baseball strike deadline set for the end of today's games.

Acting on the request of general counsel William A. Lubbers, the board decided to seek extraordinary relief for what has become an extraordinary situation.

With the strike deadline just one business day away, the board authorized Lubbers to seek a temporary restraining order, and then, if granted, a full injunction. The temporary restraining order -- which, unlike an injunction, can be issued without protracted hearings -- would postpone the strike deadline until a federal judge has had time to hear the case in its entirety and decide whether to issue an injunction.

Lubbers declined to say whether the NLRB would ask the court to compel the owners to turn over their financial records, which the players have said they need, or whether he would ask simply for an extension of the strike deadline until the NRLB could rule on the merits of the request.

Don Fehr, the general counsel of the Major League Players Association, said, "We're pleased the board is going forward. We requested them to seek some kind of interim, emergency relief, which this is. Any further reaction is going to have to depend on the precise nature of the injunctive relief they will request from the court."

The NLRB will ask for postponement of the strike deadline until 48 hours after the completion of the injunction hearings "to give the union a chance to exercise its right to strike in the event of an adverse decision," Lubbers said.

The temporary restraining order "is a request to maintain the status quo," Lubbers explained. "It is intended to give the court judge an opportunity to hear the injunction request and decide it. Assuming he grants an injunction, injunctive relief takes over until the board can rule on the merits of the case."

That is something the board has not yet done. The case will be heard by an administrative law judge, beginning June 15.

The nonetheless, for the second day in a row the owners found themselves in am embarrassing and defensive position. In New York last night, Ray Grebey, chief negotiator for the owners, said, "There is no basis for an injunction in this matter and the decision to seek such relief is an intrusion in the process of collective bargaining where the parties must ultimately resolve their differences."

A spokesman for the owners told the Chicago Sun-Time, "The owners are going to fight this. They'll take it all the way up to the Supreme Court if necessary."

In issuing the complaint of unfair labor practices Tuesday on the players' behalf, Lubbers agreed with their contention that the owners must provide the financial data to substantiate their claim of need for free-agent compensation.

Nancy Broff, the acting general counsel for the Federal Mediation Service, said, "The board has not yet made a finding on the request to turn over the books and records. The whole purpose of the administrative law proceeding is to make that determination."

For that reason, sources say, it would be unusual, though not unheard of for the NLRB to ask the judge to force the owners to turn over their records.

Another imponderable is what effect the court proceedings will have on the negotiations, scheduled to resume at 2:30 p.m. today. Kenneth E. Moffett, the federal mediator, said, "There's no question but that this is going to have some bearing on the negotiations. I'm going to go through with them and I'm hopeful the parties will be able to negotiate out their differences rather than go through with the court proceeding."

There was speculation that the court proceedings, which Lubbers said might not begin until late in the day, might prompt another day of wait-and-see negotiations. However, other sources indicated that the extraordinary ruling, coming just a day after the issuance of an unfair labor practice complaint against the owners, might give the players the leverage they needed to force the owners to make an accomodation.

That certainly was not evident in the reaction of Yankee owner George Steinbrenner, attending his team's third loss to the Birds of Baltimore: "The negotiations haven't even been negotiations. We made a proposal and Marvin Miller said no dice."

Under the basic agreement signed last spring by owners and players, the players union must strike by June 1 to exercise that option in the compensation dispute.

In charging the owners with unfair labor practices, the players had contended that the owners had made player salaries and the owner's inability to pay them an issue in the negotiations while refusing to provide the data necessary to back up that claim.

Grebey maintained that finances were never an issue. But in its charge against the owners, the players association assembled a catalogue of statements by the owners and Commissioner Bowie Kuhn that escalating salaries were the ruination of the game.

The players' attitude has been: show me. As Rudy May, the Yankee pitcher said, "They pay Dave Winfield $1.5 million a year and then they scream poverty."