Just Lonnie And Bengie
Thanks to the impeccable Bill Francis at the Baseball Hall of Fame Library, I can now merge my correct memory of the 1984 World Series with the official record, and confirm that until Bengie Molina appears for the Rangers in the first game of the World Series tomorrow, Lonnie Smith of the 1985 Royals will remain the only player in baseball history to play in a Series against a team for whom he also had played in the same season.
Left-handed reliever Sid Monge went from the 1984 NL Champion Padres to the 1984 AL Champion Tigers in midseason and was, as I recall, was in uniform during the introductions before the opener at Jack Murphy Stadium in San Diego. Bill’s clip clears all that up:
Baseball Nerd 
Pretty interesting story, thank you. Wonder if the pay was 50/50? In either event, not a bad way to collect…
What I wonder is: we often see teams go up against a former teammate/catcher in the regular season, like the Yanks against Jose Molina on the Jays, and there doesn’t seem to be much of an advantage for the catcher’s new team. When the Astros were going up against the Dodgers could Brad Ausmus tell the Dodgers how to hit Oswalt? I think advance scouting would tell you things like which pitch Lincecum throws to a left-handed hitter in a 2-1 count. The bigger deal with Big Money, as Giants fans called him, is the old line about how you always want to beat your former team. He’ll have extra motivation to hit one out.