The Major League Baseball Players Association "will file a grievance imminently" with an arbiter to protest what it considers to be collusion on the part of the owners with regard to free agency, according to Gene Orza, the union's legal counsel.

Then, next week, the union's executive board will meet to try to formulate a voluntary drug-testing program for all of baseball, board member Don Baylor of the New York Yankees told Newsday. Baylor said the union "hopes to have (a program) implemented by the start of spring training."

Baseball has been without a drug-testing agreement since the owners withdrew last October from a plan that was in effect briefly. It required testing only in cases in which a club suspected a player of drug abuse and won approval from a panel of doctors for the player to be tested.

On the collusion issue, Orza said: "We are going to file a grievance under the collective bargaining agreement, alleging that the clubs were acting in concert with respect to each other concerning the free agent process.

"The clubs got together and decided no one would bid on other free agents. It's the only logical way to explain how someone with the talents of Kirk Gibson gets no offers. If you don't believe they got together and decided this, then you probably believe that the stork brings babies."

Outfielder Gibson eventually re-signed with the Detroit Tigers.

Only two of the first 28 free agents who have signed contracts for the 1986 season have joined new clubs, Juan Beniquez with Baltimore and Dane Iorg with San Diego. The first 26 who signed returned to their 1985 clubs after not receiving offers from any other teams.

The union has maintained that the owners are in violation of a portion of the Basic Agreement. That portion -- article 18, section H -- reads:

"Players shall not act in concert with other players and clubs shall not act in concert with other clubs."

The New York Times said the grievance would be heard by baseball arbitrator Tom Roberts.