Though MLB players don't typically resent their competition, there are several bitter rivalries in the sport today. For personal reasons, certain pairs of guys wouldn't tolerate wearing the same uniform.
Some tried sharing a clubhouse before their irreconcilable differences became too much to overcome. Disdain also develops between individuals who frequently go head to head.
Fans must cherish the following soured relationships. After all, in this era of constant player movement and humongous salaries, we more frequently see mushy alliances formed off the field.
Baseball's juiciest stories involve players who will never get along.