Jerry Kapstein, who has been an agent...

Jerry Kapstein, who has been an agent for such players as Steve Sax, Carlton Fisk, Goose Gossage and Steve Garvey, has been decertified by the Major League Baseball Players Assn., the union said.

Kapstein agreed on Oct. 17 to negotiate the sale of the San Diego Padres, who are owned by Joan Kroc, his mother-in-law. Kapstein is married to Linda Smith, Kroc’s daughter and the former wife of former Padre president Ballard Smith. Bob Teaff, Kapstein’s longtime associate, also was decertified.

Eugene Orza, the associate general counsel of the union, said representing the Padres was a direct conflict of interest and that the union gave Kapstein the choice of representing the players or representing the Padres.