So we should sign any player who represents an immediate upgrade at their position regardless of what prospects are waiting in the wings? If you have player who is one of your top 2-3 prospects and is nearly ML ready, you should only block them if it's to acquire a top-flight player. Particularly if neither player looks like a fit at another position. I'm not talking about superstars, Upton wasn't even top 10 among CF in OPS last year. Behind guys like Jon Jay, Melky Cabrera and Dexter Fowler. He has a hard time making contact and doesn't hit for enough power or walk enough to move his offensive game into the "very good" range. He's a good player, but I hardly see a pressing reason to pay the guy a bunch of money when Jackson is there. Is that really so offensive? Yes, because metrics beyond OPS value him higher, and I place more stock in that bigger picture. Jackson being one of the Cubs' top 2-3 prospects is an indictment of the Cubs' system as it stands, not a ringing endorsement of the necessity of Jackson's place on the big league team. The case can easily be made that Upton IS the type of player that should be signed despite the presence of a promising but flawed prospect because you're largely know what you're getting into and he provides a LOT of value. Jackson is unproven and isn't good enough right now to merit passing on an available player like Upton simply because he's there.