Both players were drafted at age 21 and then assigned to a low level squad in the minors (Gardner went to the short season NY-Penn League, Gathright to the Low-A South Atlantic League). Both players started their age 22 season at the High-A level and earned a midseason bump to Double-A, then started the next year back at Double-A before being promoted to Triple-A in the middle of the season. In their age 24 season, their third full professional season, each player started the year in Triple-A before being called up to the big leagues during the summer and finishing the year there.
The fun doesn't stop there, though. After breaking down their career statistics, both from the minors and the majors, RAB seems to think Gardner will outperform Gathright in the long run, so to speak.
[W]e can expect Gardner to be a more productive big leaguer than Joey Gathright. He’s shown better on base skills and a better ability to hit for power throughout his minor league career, and he’s a much more efficient basestealer. Simply put, Gardner’s proven to be much more capable of turning his physical gifts into baseball skills, and in turn, offensive production.
I, for one, would be satisfied if Gardner produced at a level equal to that of Gathright. That he might even be a better all-around player gives me even more hope for the upcoming Yankees season. Although Gathright's career numbers aren't anything to write home about, if Gardner produces at or above a similar output, he won't exactly kill the Yankees as a regular center fielder, even if he's splitting time with Melky. Based on RAB's analysis, Gardner might even help the Yankees-- or least land them a pretty good lefty reliever.