Truth be told, you never really know. Not in baseball. Shortstop Jean Segura was an All-Star at the age of 23 with Milwaukee, then one of the worst hitters in the majors for two seasons. Now with Seattle, he is an All-Star again.
As rookies, Will Middlebrooks and Dustin Ackley turned in performances of the type that many expected out of Scott Kingery this season. By the age of 28, both were major-league castoffs.
The reality of the sport does not get any less baffling with time. The longer you are around it, the more pessimistic you become with regard to anything that you think that you know.