Ruben Sierra. Ruben was great for confrontations with his managers, and was labeled by Tony LaRussa as "the village idiot" after Sierra told LaRussa (at the time the A's GM) that he (LaRussa) did understand baseball because he had never played it himself. The Village Idiot (Sierra) was later branded by Joe Torre (over rated Yankee's coach) as the only player not to understand the team concept.
Sierra: "Hey, LaRussa, you don't know sh*t about baseball."
LaRussa: "Sit your ass down and inject McGwire with those steroids, village idiot."
Sierra: "Yes, Sir."
LaRussa: "And hey, dumbass, you sure do keep some big gold."