David Stern, commissioner of the National Basketball Association, predicted yesterday that Congress would not pass any legislation on franchise relocation this session. He also said the NBA is likely to expand in two years if the league continues on its pace of profitability.

"For every city that's about to lose a team, there's a city that wants a team," Stern said at the Washington Journalism Center's conference on the big business of sports at the Watergate Hotel. "So there's going to end up being some kind of an even split amongst the powers that be.

"We haven't done that kind of a head count, but I think it's a serious subject that merits some attention . . . It would be a good idea to let sports teams relocate without antitrust liability. But if that isn't the case, fine. Let us be, and we'll manage quite well, thank you."

Stern said leagues that do not control movement are making bad business decisions. "If sports leagues become viewed as places that will move from one place to another in search of a fast buck, that's bad business," he said. "It ultimately will be stopped by the league itself or the league will decline in popularity."

Stern, the opening speaker on the three-day program, said the league will expand when at least 20 of its 23 teams are profitable. He said current projections put that as "the season after next."

He did not discuss how many teams or where.

In other developments, Don Fehr, acting executive director of baseball's Major League Players Association, said it would be at least 60 days -- and possibly longer -- before his group considers a strike against the owners if agreement is not reached on a new collective bargaining agreement.

"The executive board can set a strike date any time it wants," Fehr said. "We consciously have been trying to avoid giving signals that we expect, or want, or are looking for a confrontation. We don't have much to prove. If the owners don't now understand after 1981 that the players are willing to strike at midseason if they have to, then taking a strike vote in March isn't going to impress them any more than that."

Dr. George Lundgren, editor of the Journal of the American Medical Association, who has championed the abolition of boxing, predicted that by the end of this century "most, probably not all, states" will have outlawed professional and amateur boxing because of its risks of brain damage.

"Why? It's the right thing to do," he said. "And I quote what Winston Churchill said: 'You can always count on the Americans to do the right thing, after they've tried everything else.'"