Cardinals have the best system in baseball right now in both depth and upside, but it's lacking the one thing nearly everybody is lacking: quality shortstops. Rangers have a very good system that's long on pitchers and short on impact bats.

Prospect for prospect trades are so rare, but this idea kind of caught people's attention this winter and enough folks wrote articles about it that Mozeliak actually commented on the idea during an interview with Jim Bowden this spring. He apparently said he'd "have to think about it" if the offer came up.

http://www.fangraphs.com/blogs/jurickson-profar-for-oscar-taveras-a-thought-exercise/

>Interesting, I hadn't heard the Tavares for Profar talk, it
>will be interesting to see what the Rangers do with him seeing
>as how they just gave $120mil to Elvis Andrus who's currently
>batting eight right now, lol

Yeah. I get the reasoning, that Andrus' glove and more-than-acceptable-in-the-post-Jeter/ARod/Garciaparra-era bat justified the extension. But it seemed like they didn't quite consider how south the bat could go. And it's ... pretty far south.