I dunno... Over the previous 4 consecutive seasons, he had 503, 651, 590 & 690 plate appearances. He batted .307, 307, .260 and .301 during those years. IMHO, that is a pretty solid track record. He turns 30 this October which is really when a player is in the middle of his prime playing years.
I really don't believe the Dbacks went too far out on a limb here, based upon Prado's historical performances... Of course, he is not at all comparable to the type of production Upton is capable of producing - and I really don't think the Dbacks saw Prado that way.
They simply knew they needed to part ways with Justin and in the end, Prado represented a value they were comfortable with (along with Delgado)... Given Upton's irratic - at best - performance this year and over the course of his career, I remain comfortable with the decision that was made... HOWEVER, it goes without saying that Prado's sub-par performance thus far has been hugely disappointing. There is no other way to say it - he has absolutely SUCKED thus far... But then again, so have Miggy, Ross, Kubel and others...