To a small degree yes, you have to have some facility to be able to move about the instrument, but more importantly, the "strong brain signal" that Hal Galper is talking about that I linked to is the most important.The physical aspect of playing is. The mechanical part of playing a scale, line, arpeggio, etc has to be mastered before your psyche can be engaged, you have to get past the physical part of learning to play. To get it under your fingers, as it were.
Using my imagination, I can play note combinations that I never practiced before, and execute them sometimes as if I did actually practice it. Of course it depends on how you define mastery. I'm not a master of playing blues scales, yet I'm able to play bluesy lines at tempo in a live setting.
The diff is that I'm letting my ear be my guide, screaming that sounds in my head, and forcing my body to cooperate. Muscle Memory doesn't even come into the picture unless I can't think of something to play and let my hands run until I can come up with something. Unfortunately, the other side of the coin is that I don't hear very complex lines, so the stuff I play is pretty inside but I try to make it swing as much as possible.