Drug testing in MLB 2013: Major League Baseball expands testing for HGH

Major League Baseball and players have agreed to ramp up the battle against illicit performance-enhancing drugs by instituting in-season testing for human growth hormone.

The league and the Major League Players Association, in a statement Thursday, said unannounced, random blood tests for human growth hormone -- known as HGH -- will begin this year.

HGH is not approved by the Food and Drug Administration as a treatment for sport injuries and is banned by most professional sports leagues.

The agreement also calls for enhanced efforts to detect testosterone.

A previous agreement allowed testing for HGH during spring training, in the off-season and for reasonable cause. The testing now will include the regular season.

"This agreement addresses critical drug issues and symbolizes Major League Baseball's continued vigilance against synthetic human growth hormone, testosterone and other performance-enhancing substances," Commissioner Bud Selig said in the statement.

Michael Weiner, executive director of the players group, said, "Players want a program that is tough, scientifically accurate, backed by the latest proven scientific methods, and fair; I believe these changes firmly support the players' desires while protecting their legal rights."