Which player do the Reds need to take his game to the next level the most? For me the answer is: Brandon Claussen.
Claussen needs to make the same leap in performance that Harang did last year. If his numbers come close to Harangs 2005, then we have the makings of a rotation starting to happen. Wilson will not be with the club in '07, and may not be there this year either. Dave Williams is under contract for this year I believe, but the reds own his rights for a while. Milton... sigh.
So for me the biggest improvement needs to come from Claussen.