NFL players are being warned by the league about the possibility of foreign meat products containing a certain performance enhancing drug. The PED under question is clenbuterol, which is banned under the league's performance-enhancing substance policy.

In a memo sent to NFL players yesterday, countries like China and Mexico have been listed as countries that use the drug in their meat. Clenbuterol is used as a muscle-building and weight-loss stimulant.

"Players are warned to be aware of this issue when traveling to Mexico and China," the memo read. "Please take caution if you decide to consume meat, and understand that you do so at your own risk...consuming large quantities of meat while visiting those particular countries may result in a positive test."

Texans left tackle Duane Brown tested positive for clenbuterol last season after a bye-week trip to Mexico. The Texans now play the Raiders this upcoming season in Mexico City.

Clenbuterol is banned from Mexican cattle ranches, yet it is believed the drug is widely used.

What do you think of this latest memo sent to NFL players?