Major-league baseball teams will start selling approved supplements to players in an effort to prevent positive drug tests. Management and the players' association are having NSF International, a company based in Ann Arbor, Mich., certify that products are clean. Once a supplement is certified, teams will buy the products and make them available for resale to players in the 30 major-league clubhouses. "They do all of the auditing and testifying of the products and certify they are clean," management lawyer Frank Coonelly said Monday. After meeting with New York Yankees players for nearly two hours Monday, union head Donald Fehr discussed the certification process. He also talked about revenue sharing, likely to be a contentious issue when the union and management start bargaining over a labor contract to replace the one that expires Dec. 19. Commissioner Bud Selig advocates that teams should increase the amount of shared money, currently 34 percent of local net revenue. "I don't see a need for increased revenue sharing," Fehr said, adding that revenue sharing and the luxury tax discourage teams from growing revenue.