From "Crowded outfields make for interesting managerial decisions" by John Donovan at SI.com:
This is an awesome time of the year for playing around. Hitters do it with their stances. Pitchers fine-tune their deliveries. And managers do it with just about everybody and everything that they can get their manipulative little fingers on. If there's a big-league manager out there not fiddling around with his lineup card right now ... well, he's just not doing his job.
In St. Louis, manager Tony La Russa -- a man who has fashioned a Hall of Fame career out of doing things his way -- has started this season juggling not three, not four, but five outfielders. Mike Scioscia of the Angels is trying to get four established, All-Star outfielders regular at-bats, though that's much easier to do in the American League, where someone can be relegated to designated hitter duties for a day.
New Dodgers manager Joe Torre has a couple of high-priced veterans that he's trying to mix in with a couple of kids that he needs to see in the outfield. Boston manager Terry Francona is trying to get both rookie Jacoby Ellsbury and superb fielder Coco Crisp their time in an outfield that is already two-thirds full.