Here's a shout out to fellow SB Nation baseball blog Minor League Ball, written by John Sickels. He published his prospect rankings on Friday. The Tigers landed two prospects among the top 120 -- and you need not spend too much time worrying which two, because you know which two.
As with all such lists, the trick is finding a balance between short-term expectation, closeness to the majors, and long-term potential. A list that looks at nothing but long-term upside will look much different than a list focused on players poised to make a quick impact. This list is a hybrid of the two types and some of the rankings will reflect that.
That's why I prefer a list like Sickels to one that focuses only on ceiling, no matter how unlikely that ceiling is to actually be achieved.
Jacob Turner came in at 18th. He was the eighth right-handed pitcher named. (If you want to DQ Yu Darvish, then Turner was seventh.)
Further down, third basemen Nick Castellanos ranked 59th.
LHP Andy Oliver, LHP Casey Crosby and LHP Drew Smyly all earned "also considered" mentions.