I was tearing off sheets for my daily calendar which lists achivements in baseball, when I encountered the following:
July 19, 1911 Walter Carlisle makes an unassisted triple play for Vernon of the Pacific Coast League. What's so unusual about that? Carlisle is playing center field at the time.
Blink blink. Here's some additional information. Unfortunately, it wasn't in the major leagues, so you won't find it on Baseball Almanac's page of unassisted triple plays.
Carlisle also apparently played for the 1908 Red Sox, but recorded only 10 AB with 1 hit, 1 walk for a career average of 0.100 in the major leagues.