MLB players have been issued a warning over the use of deer-antler spray, a substance administered under the tongue that includes a banned chemical known for its muscle-building and fat-cutting effects, SI.com has reported.Players had felt free to use the spray at nearly no risk until the warning was sent last week by the league, the report said.In its warning, issued in reaction to reports from the drug-testing industry, MLB requested players not use the spray because it contained "potentially contaminated nutritional supplements" and had been added to the league's cautionary list of products.The warning was not issued because the spray includes the banned chemical, SI.com reported. Source: ESPN
