He argued that the substance was found in an asthma medication he was prescribed but chose not to contest the 2 - year ban .
In June 2009 , Gray tested positive to clenbuterol , a banned substance .
Gray argued that the substance was found in an asthma medication Gray was prescribed but chose not to contest the 2 - year ban .
In June 2009 , Gray tested positive to clenbuterol , a banned substance .