The Federal Mediation and Conciliation Service agreed yesterday to enter what Deputy Director Kenneth E. Moffet called a "crisis situation" in the contract negotiations between baseball owners and the players' union.

Moffett said the FMCS was asked by the owners to intervene yesterday morning, and that the union had agreed with the move.

Both sides are to meet Sunday with Moffett and Commissioner John Courtney in Palm Springs, Calif., "in an effort to sort out the issues and possibly resolve those in dispute," Moffett said.

Palm Springs was selected because Marvin Miller, executive director of the Major League Baseball Players Association, will be meeting there Saturday with the last of baseball's 26 clubs to take strike-authorization votes.

With the exception of one unidentified player, 829 on the 22 clubs polled so far have authorized their team representatives to call a strike when the MLPA meets in Dallas on Tuesday, eight days before the scheduled season-opener.

While a strike could be called then, there has been growing support among the players for delaying until later in the season when the owners' pocketbooks would be hurt more.

"I don't know if I can head off a strike vote," Moffett said. "I'm going to review the issues and just see where they are and see if there's any possible movement as far as either side is concerned prior to a strike vote.

"Any time you have a crisis situation -- whether it be a strike vote or an actual threat of a strike, and you have both in this instance -- there's always a possibility for some movement on both sides. But I won't know until I get there."

Moffett said the FMCS has been monitoring the negotiations for several months. "Obviously, they are stalemated and need help," he said.

He declined to speculate on what might happen if no progress is made at Sunday's 1:30 p.m. session, which could go until 8 a.m. Monday, when Miller is scheduled to fly to Dallas.

But, Moffett added, "Once we get called into something we generally stick with it until it's been resolved one way or another."

In Scottsdale, Ariz., where both sides were still at the bargaining table yesterday, Ray Grebey, head of the Major League Baseball Player Relations Committee, the owners' unit, maintained there was no reason for a strike.

"In the opinion of the 26 clubs," Grebey said in a telephone interview, "there is absolutely no reason for a strike.

"Baseball played baseball and continued to negotiate in 1976 until after the All-Star break. In basketball, your Washington Bullets (and the entire NBA) are playing this entire season without a new, signed collective bargaining agreement and they haven't been running to the press to make an issue out of it. They've been trying to work out their problems and have. Football also (played without a contract) for three years."

Grebey, who briefed the owners Tuesday on the status of the talks, said, "Their resolve remains as strong as when we started negotiations."

The former chief of labor relations for General Electric, Grebey added that "as long as the (baseball) negotiations continue, there is a basis for guarded optimism."

Union chief Miller, reached in Scottsdale last night, said the two sides "are far apart and there has never been any real bargaining, ever."

Mediation, Miller continued, can be "an aid to collective bargaining. It never be a substitute for it. But I don't want to prejudge . . . I don't care how skilled a mediator is, the first essential is that he have an understanding of all the issues. In half a day, to ask somebody to grasp all the issues is going too far. That's really taxing it."

Miller, who refused to predict what Tuesday's strike vote might be, said that any long-term mediation by the FMCS would be "exactly what the owners expect the mediation service to do, stall some more. It would be more of the same foot-dragging we've had from the owners for the last 20 weeks."

The major issue separating the two sides is the question of free-agent compensation. The owners want a team that loses a highly sought free agent to be able to pick a player from the free agent's new team.

Under the owners' proposal, the free agent's new team would be allowed to protect 15 players on its roster. The players contend that few teams would be willing to sacrifice their 16th-best player in order to sign a free agent, thus diminishing the players' opportunities in the open job market.

Also in dispute is the amount of time a player must serve before he can become a free agent. The owners want to maintain it at the current six years; the players want a four-year minimum.

Other issues to be resolved involve whether a player with four years of service or less should be restricted to a one-year contract, whether an arbitrator should weigh a player's time and service more than his performance when ruling on salary disputes and whether players should get a cut of baseball's television revenues, estimated at about $180 million this year.