It depends on many factors.
We must take into consideration the position of this fellow ( ofcourse if sb has bet before him and forced him to shove , but from what you say someting like that never happenned ) , if he has shoved from UTG or MPor BU is important to know .
We also need to know whether he has shoved before , if he has reached showdowns much before with what
hands he did , how loose or tight he is ...
But generally I , with 20 BB , 8 M if I 'm not wrong , I would not choose to shove here , but wait for a better hand from position . I don't think it's time for flip with an open shove , but that's my opinion
.