A couple of comments from Kevin Goldstein following the draft, but before Purke's signing:
Matt Purke is still the biggest mystery of the draft; he entered this year with visions of being considered for the top overall pick. Blisters hampered him early, but then he developed shoulder problems, a far more concerning issues. He tried to pitch late in the year, but his stuff was nowhere close to what teams saw last year, when he want 16-0 for TCU.
http://www.baseballprospectus.com/article.php?articleid=14417