Juan Nunez, who allegedly was responsible for the scheme to explain away Melky Cabrera's positive drug test, has been banned from major-league clubhouses, according to an ESPN.com report.
Major League Baseball circulated a directive Tuesday to keep Nunez from "clubhouses or all non-public areas" of all 30 major league parks.
Reports have alleged that Nunez, a consultant for Cabrera's agents, was the instigator of the plan to create a fictitious supplement and fictitious website to help Cabrera avoid suspension for his positive test for synthetic testosterone.
Major League Baseball has not officially confirmed reports of Nunez's involvement in the scheme, but Cabrera was suspended for 50 games for his offense.
One club official told ESPN.com that the directive tells teams that Nunez is "not certified as a player agent" by the Major League Baseball Players Association.