Testing for human-growth hormone was instituted during the offseason a year ago, and MLB would like to add the ability to test for HGH during the regular season and to use enhanced procedures to reveal elevated testosterone levels. The current agreement on drug testing is part of the Basic Agreement.
"[The union] is very open to making additional changes," an MLB source said.
Baseball has been at the forefront among professional sports leagues in attempting to deal with the use of performance-enhancing substances, proposing the use of more sophisticated tests that not only note changes in the approved ratio but can also differentiate between natural and synthetic testosterone.
Several players were suspended recently for use of testosterone, including Giants outfielder and All-Star Game MVP Melky Cabrera, Athletics pitcher Bartolo Colon and Padres catcher Yasmani Grandal. Cabrera has since signed with the Blue Jays as a free agent. Milwaukee's Ryan Braun, the 2011 National League MVP, tested positive that year and won an appeal on procedural issues.
Minor League players have been undergoing blood tests for HGH for three years. Major League players have had the opportunity to grow more comfortable with the process during the offseason and in Spring Training.
Michael Weiner, executive director of the MLBPA, signaled a willingness to accept stricter testing this week after the union's annual executive board meeting in New York.
"We've had discussions with MLB about some ways to make the deterrent stronger," he said. "I would expect that you'll see, before too long, some announcements in that area.
"Testosterone appears to be a problem, or the use of testosterone by some players, and there are some things we've talked about to make sure the deterrent on testosterone is as strong as it can be."
MLB and the MLBPA meet jointly each year to discuss the drug-testing program with the independent program administrator. To this point, there have been preliminary meetings, but the formal negotiations will be held in the coming weeks.
The penalties for failing a PED test apparently will not change: a 50-game suspension for a first offense, 100 games for a second and a lifetime ban for a third. Both Commissioner Bud Selig, at the Owners Meetings in Chicago earlier this month, and Weiner this week said they believed that the sanctions did not need to change.
Paul Hagen is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.