It's extremely, extremely rare to convert a position player to pitcher, or vise versa, by the time a player reaches the MLB level. (Rick Ankiel is the only one who comes to mind.) 

I think Hicksie will get one more audition for a 25-roster spot. His winter league results do not bode well for him, however. 

Agree with Hosken. Hicks hasn't pitched in seven years. No way is he going to become a pitcher now. Ankiel switched from pitcher to hitter, Tim Wakefield switched from minor league hitter to knuckleballer. There have been a couple others, but none that I remember switching at the stage of career Hicks is at.

I am convinced that this still-young guy needs to master Triple A. Perhaps then he can move up to the majors and fulfill some or most of his potential.

Although the clock is ticking, there is still time for him, just don't count on him for 2015.  Start him in AAA, make sure he gets some time in left as well as center and keep your fingers crossed.  Because he could be a potentially superior defender, he could be a contributing MLB player with lesser offense.