Dave has announced that AAA "center fielder" Jamal Strong tested positive for a banned susbstance, and will be suspended for ten games.
The most common misconception about steroids is that their main (sole?) purpose is to bulk up in order to be stronger and hit more home runs. However, this simply isn't true, as anyone with any knowledge of track & field or, more prominently, the East German doping machine of the 1970s and 80s could tell you. Along with decreasing body fat content, steroids reduce recovery time, allowing a person to train harder and more frequently, thereby giving him a competitive advantage over another person who is held back by his body's natural limits of exertion.
It's not all about brute strength. Since steroids were first given to unsuspecting German pre-teen Olympic swimmers decades back, scientists have known them to be able to increase endurance and quicken muscle response times. As more and more baseball players get caught for taking PED's, you aren't going to see as many power hitters getting suspended as so many people would like to believe. There's a reason for this, but it just has yet to capture public attention.
Update: The Times has confirmation.