He's a credible center fielder, and his career hitting numbers look a lot better if you ignore the Atlanta and Toronto stints. (Tampa: 105 OPS+; San Diego: 102; Atlanta: 66; Toronto: 54.) Is Oakland more like Tampa/San Diego or more like Atlanta/Toronto? This is a tough one.

Also, you'd normally say something like "wouldn't we rather be playing the kids?" But remember that we're talking about Jaff Decker as the eventual fifth outfielder, so the real question is whether we'd prefer to give Upton a shot at that role rather than Decker, at what you figure is probably approximately the same cost.