Within Zach Levine's Minor League Notebook we see the logic behind moving 26-year old Yordany Ramirez to the mound.
"It came to fruition that now was the right time to take on that challenge. We're not sure where it's going to take us at this point but he's willing to do it and we're going to take the time to see what he can do on the mound."
Ramirez, in nine seasons, is a career .246/.277/.365 hitter, with 419K:87BB. He just isn't a viable prospect as an outfielder (as Levine notes), but I suppose it says something about what the Astros perceive as his athleticism that they're willing to give it a shot.