The National Football League Players Association warned players against steroid-contaminated meat from China and Mexico, saying eating large quantities could lead to them failing drugs tests.
The NFLPA said in a statement sent to members that players remained ultimately responsible for what they put in their bodies.
"There is some evidence that some meat produced in China and Mexico may be contaminated with clenbuterol, an anabolic agent which is banned by the NFL Policy on Performance-Enhancing Substances," the letter reads. "Consuming large quantities of meat while visiting those particular countries may result in a positive test for clenbuterol in violation of the Policy.