Fourteen of the National Football League's 28 teams already have voted overwhelmingly to authorize a strike by the players' union should current negotiations with management fail to achieve a new collective bargaining agreement, the union said yesterday. But it named only three of them.

Ed Garvey, the NFL Players Association executive director, also said that the NFLPA has decided to strongly oppose the NFL antitrust bill introduced last week by Rep. Fortney H. (Pete) Stark (D-Calif.).

And Garvey charged that most league teams are not bargaining in good faith with veteran players who became free agents Feb. 1 under the current collective bargaining agreement.

Garvey did say, however, that the NFLPA has accepted a league interpretation of that agreement and will represent all players in negotiations when the contract expires July 1, thus eliminating individual bargaining by athletes after that date until further notice.

Regarding the strike vote, Garvey said he expects to hear from the rest of the 14 teams within two weeks. Players are being asked to sign team petitions granting the NFLPA executive committee the right to call a strike at any time during the bargaining process.

Garvey said NFLPA, which needs two-thirds approval of its membership to call a strike, decided to gather the petitions at this time to counter a flood of what the union considers negative publicity regarding player opposition to NFLPA bargaining demands.

The union would not name all the teams that have replied, other than to identify the Redskins, Green Bay Packers and Kansas City Chiefs.

Garvey said NFLPA player representatives, who concluded a four-day meeting here yesterday, held in part to go over plans if a strike is called, voted unanimously to oppose the Stark bill, which is aimed specifically at nullifying a court decision clearing the way for the Oakland Raiders to move to the Los Angeles Coliseum.

The bill declares it is not a violation of federal antitrust laws for professional sports leagues to require members' approval before a team relocates. The bill also would permit pro teams to share revenues without threat of a lawsuit.

Although the NFL considers the bill to be narrowly written, Garvey said it "would have an impact on players now and in the future. The real issue is how do you protect fans from NFL clubs which move from city to city. We'd like to see a bill that outlines the points under which a team could move, such as falling attendance, poor facilities and so forth. We also believe that the revenue-sharing aspects will give them a special status, the ramifications of which can only be determined through yet more court tests."

The NFL maintains, however, that the bill will not affect the league's relationship with the union, and will not hinder players from suing the NFL. The league considers the bill essential to stop wholesale franchise shifting in the wake of the Raiders' court victory.

Jack Donlan, NFL Management Council executive director, was not available for comment. Spokesman Jim Miller said, "It is not our policy to comment on the internal workings of the NFLPA."