Ummm...
I have my doubts about that. I'm inclined to think that there's some particular "use regimen" that has the reputation of being undetectable - but that it's "not quite" undetectable, or that it's very vulnerable to carelessness, or some such.
If you can't imagine a player like Gordon doing this knowingly...that implies that you don't believe PED usage in baseball is fairly widespread...that you believe the "few" who use PEDs have generally been caught. I'm skeptical.
Back in the day (the 1970s), amphetamines were reported to be openly available in MLB's locker rooms. These drugs were illegal, but they were there - and they weren't being sneaked in by misbehaving players. They were believed to improve performance, so they were made available and they were used. I see no reason to believe that the underlying attitudes about drug laws, MLB rules, or long-term health that prevailed in locker rooms in the 1970s have somehow changed; I suspect that more players than we want to think about are in fact using whatever they think they can get away with that might improve their performance.
The difference between the minors and a berth at the end of a 25-man roster is a half-million dollars a year. Advancing beyond the end of the roster to something like everyday play is worth literally millions of dollars a year. Young men with a high-school education (or three years of college majoring in parks and rec) have few prospects outside of baseball, and none that can remotely compete in terms of financial return. It's perfectly rational to do whatever you can to improve your chances of moving onto or up that roster - even if there's a risk of a suspension. The potential return is so great that I might argue that it would be foolish not to use something (or at least seriously consider it).
Freddy Galvis. If he hadn't used PEDs, and never developed any power, he'd likely be in the minors - or else out of organized ball by now...back in Venezuela, age 26, no particular skills. Given the turmoil in Venezuela, he'd likely be wondering how he was going to feed his family. Instead...he's earning $2 million this summer. This is a no-brainer.
The public comments? The "I can't believe he'd do that; he's such a good kid, such a hard worker," yadda yadda yadda? Spin.