It’s interesting that only MLB caught Yasmani Grandal and the minor leagues did not. Both test. I remember Mike Morse claimed he got suspensions from both for the same infraction. He ended up having to serve multiple suspensions even though an arbitration panel admitted it was probably unfair.
That could mean that Yasmani took this later in the season, around the time he got to the big leagues. This would likely point towards him taking it to heal from his oblique injury. Testosterone helps muscles grow quicker. Or to combat the fatigue of the season. Both taint his numbers, but are a little different context than just bulking up in the offseason.
Another conclusion is that he was cycling on and off as is sometimes done when taking steroids (steroids produce high levels of testosterone, so it’s possible he was taking steroids). Part of the reason to do this is to hope to get tested when cycling down. He could have been doing this and then got unlucky. This scenario would be closer to what you think of when you hear "performance enhancers". Knowingly using PEDs to pump up your performance by increasing your physical potential.
Of course, we don’t know when any of these tests were. Perhaps he’s just been juicing constantly and finally got busted.
The sad thing is that Grandal has been a remarkable young player and the fast path to becoming a major league standout. How much of that do we trust when projecting any future performance, because like it or not he is still in the Padres future plans.