Major League baseball recently announced that it will begin mandatory testing for steroids next season. The league said that between five and seven percent of its players who were tested this year tested positive -- and that level triggered a provision in the new labor agreement stipulating mandatory testing. Baseball's new "get somewhat tough" approach is just one story in a flurry of recent news involving athletes and the use of performance enhancers. Dr. Jon Hallberg is a team physician for the Minnesota Twins and medical director of the University of Minnesota primary care clinic. He says the new testing policy could reveal just how much steroid use there really is in the major league.